SOME MINOR EASY-TO-IMPLEMENT SUGGESTED UPDATES FOR MUSESCORE:

"Don't ask what MuseScore (and its user community, contributors and developers) can do for you, ask what you can do for them!"
(free after John F. Kennedy).

• As far as I can tell you haven't yet helped to answer a single user's question.
• Regardless of your alleged 25 years experience with programming have not yet contributed a single line of code.
• You have not helped in translating the handbook or the software itself into your mother tongue, your native language (the Bulgarian translation definitely needs help, and there you could even add the mnemonics you're missing, actually I just did add the ones for Save, Save as and Print the other day).

Instead your boasting about your vast knowledge and experience, resort to personal attacks, apparently largely due to not having read and/or understood the replies (as short, concise and to the point as they were) and write overly long and convoluted essays (including a rather long footer time and time again that is not needed at all) rather than single short concise topics. On thread per issue you have, not one thread starting with 5 issues, which you then extend to 13! And then you call that 'professional behavior' ...

I'm working in technical customer support since more than 25 years now (and no, not with MuseScore, here I'm just a mere mortal volunteer and contributor, and that since more than 10 years), but never in my life have seen or experienced such inappropriate behavior with any of the customers I had to deal with (actually not quite true, it happened once, and I did put the phone down on that customer, he apologized on the next call). At work though I'd have not much choice that to deal with it, but here I have that freedom, EOD.

> If you have 10 years of both composing and programming then MAYBE you can imagine how it is to have 25 years in both (like I have): can you?

Since you're adamant on comparing sizes; You asked for at least 10y and I indulged you. So fine, here are the specifics if you really want: I have 27 years of musical experience and 17 years of programming experience. Hopefully this information now satisfies your thirst for establishing such facts as if they are relevant to the discussion at hand.

> My advices for flexibility and generalizations (of both the “linked” and the “cross-staff” concepts) (see thread https://musescore.org/en/node/311588) may come from your distant future (because they are condensed from a far larger experience), believe me! It's clear for me that my ideas come from your distant future simply because you are not visionary enough to transform MuseScore (MS) in an almost perfect “jewel”.

The "issue" with both of those proposals is that first and foremost you didn't seem to even understand what a linked staff currently is. And from all of your scattered replies it still is very unclear to me as to what you want to "generalize" this into. Because if it's just to apply an octave transposing key to them, then what's holding you back to not currently just doing exactly that?
Secondly you wish to expand on the cross-staff concept; but your proposal so far makes no musical sense. I have asked for a use case for this beforehand, and none have been provided.

> You still have obvious problems to learn basic smart facts/approaches from Sibelius and Finale and to also implement them in MS!

Just for your pleasure I looked up cross-staff notation in the manuals of Sibelius, Finale and Dorico. Interestingly enough all of them also only allow for that within staves of the same instrument and only to an adjacent staff. Dorico especially mentions that this is only possible within a grand staff.
So how again is MuseScore not doing these basic smart facts?

> Sadly, complacency seems a speciality for both Mr. “Jojo” and you. Out-of-the-box thinking is also not a quality of yours either: that's clear!

Ah yes, unfounded slander, the base of every validly argumented discussion.

> Consider this as truly my last answer: my generosity (with my time and patience) has limits and you’ve reached them.

What you do with your time is your choice. It might be because English isn't your first language, but considering replying to questions for clarification a generosity on your part comes across as a slight god-complex. But I'll just assume that this is due to the language barrier and try to carry on by focusing on the actual discussion.

1. >I cannot pay attention on all the replies and comments as long as Mr. “Jojo” literally bombards me with N^2 one-line low-value messages. This is FAR from a professional attitude and approach! If you and Mr. “Jojo” both work in the same technical team of MS then, it would have been a much more professional attitude that you firstly analyze my proposal, create a common answer (after putting you in agreement with each other, because there are obviously disagreements between you both!) and THEN come with an answer: that is being truly professional, which is not your case.

Neither Jojo nor myself are part of the MS team. We're first and foremost rather experienced users. But as MuseScore is open source and we are programmers, we both are also volunteering contributors to the code.
Jojo indeed can be concise in his replies, but that doesn't mean you have to jump on each and everyone of them right away (I know I don't).
Take your time to process the replies and then post your responses if you so desire.

It is precisely due to the open nature of MuseScore's development that we are able to discuss our view out here. And yes, often not everyone involved in development is in agreement with every decision. On some points we do, on others we don't and try to work out (often here in the open) together with our users what approach would be best for the product.

2. > However, you’re clearly a BIT more open-minded than Mr. “Jojo” to whom I have an additional info to give: the windows dedicated to establishing “Advanced style properties” (opened from the “Stave properties”) (which also establishes the number of lines for a chosen stave) ALSO DOES NOT allow rescaling and also disappears when rescaled (like the Preferences window)

Logged as #311713: Advanced Style Properties minimal height excessive so it may get fixed in a future release.
Resizing a window though has not ever made it disappear to my knowledge; I have seen some window managers where the window gets reduced to a very small bar at the bottom of the screen or gets placed underneath the main window, so do make sure that is not the case for you.

3. > Proposing me various “workarounds” instead of fundamentally and profoundly correcting the bugs of MuseScore (or at least accept that they should be applied elegant solutions, not improvisations!) ISN’T a professional method either, but more an “artistic”/improvisatory one: thus try to update your pragmatism with some elegant long term solutions to those reported errors! You have the tendency to find excuses for almost any reported bug (and tend to apply the 3-step technique: denial of the problem, minimization of the problem and then faintly whisper that “yes, there may be a problem and a solution to it!”; and that’s not professional either). I rarely found a situation where a programmer of MS to firmly (and manfully!) recognize: “Yes, that’s a problem that definitely needs to be solved!”. You’ve transformed this discussion in a kind of Turkish “bazaar” in which you persistently negotiate anything and tend to hide (by ignoring them in your answers) some flagrant reported bugs.

Your opening post of this thread mentions 5 items, none of which are bugs. They are all suggestions for improvements: "recommendations" you called them. The facts here work against your statements and the issue tracker is filled with reports as a result of developers straight up saying: "yes this is a problem".
Again, let's try to keep focus on the actual requests and issues, shall we? After all, your time is limited and precious..

4. > You have spoke not even a word on the bug I’ve reported on MS NOT allowing to add a “linked stave” to the bass/F-clef line of a piano score: thus you’re highly selective in what you reply (and clearly avoid talking about some obvious bugs of MS) and that’s not professional or shows a low degree of rigour (thus of professionalism)

Right back at you: https://musescore.org/en/node/311588#comment-1032591 point 2.
First off: this doesn't even concern the topic at had but is about another topic of yours. Once again, it helps discussions to keep them on topic.
If you can't be bothered to read my replies that's one thing, but then going on and calling me out for not replying is a blatant lie. Especially if the reply gives thought to 2 other related use case scenarios that you've likely overlooked as much as the current MuseScore implementation has overlooked them.

> (Americans and English are NOT Germans, that’s for sure!)
Not quite sure what this statement is supposed to mean at all. But as you're so keen on comparing personal information: You've been corresponding with a German (Jojo) and a Belgian (myself). Again, not that this had any relevance to the discussion at hand..

5. > I’ve proposed you a generalized concept of “linked staves” (not to mean just “mirror/clone” staves) [...]

A "linked staff" is indeed a very rigid concept, purposefully so.
If by your proposal you mean this post (again, a completely different topic then the one at hand in this thread...) then so far, from what you've written you've mostly just defined staves belonging to the same instrument. Something that has been part of MuseScore since v1.

> [...] and a generalized “cross-staffing” between distinct instruments (with timbre change [if wanted by the user], not only position change)

As mentioned a few times, such a notation doesn't make any sense musically speaking. Please provide examples or use cases for where it does.
So far the only use case has been "to test out sounds", for which (to put it very bluntly) this would simply be the wrong solution. Moreover so because sounds are not solely defined by the instrument staff something is notated on (just have a quick look at the many different piano sounds available by default).

> these are out-of-the-box approaches which clearly remove you from your comfort zones!

It's not my comfort zone that's being targeted by your proposal, it's the current musical meaning and definition of some usages. And yes, I'm not too keen on changing the musical notation system just for someone who doesn't want to turn on loop playback and use the mixer to change sounds.

6. > There are also piano scores with 3 (or even 4) parallel staves: why doesn’t cross-staff function allow to move a note between the 1st and the 3rd stave for example? (it just limits me to move a note between the 1st and the 2nd one, or moving a note between the 2nd and the 3rd one, but not between the 1st and the 3rd and vice-versa): that is a easy to solve issue I think! (I somehow workaround this bug in my demo on the periodic musical staff https://musescore.com/user/363391/scores/6391390 )

It doesn't allow that because cross-staff notation is to an adjacent staff by definition. I personally would be fine though with allowing cross-staff notation between all staves of the same instrument, so feel free to put that suggestion into the issue tracker.
For what it's worth, I wouldn't have used any cross staff notation at all to create your PMS examples, but entered the notes on their own staves directly. You also might want to use the inspector to set the height for that fixed spacer explicitly so that the spacing is correct; you've now likely dragged it with the mouse and eyeballed it, resulting in the G4 of m7 not really ending up on the line it should, make it 2,60sp.

7. > I invoked my 2-year-old son and MS version 10 because of my past experience with MS: it’s almost 2 years since I’ve reported the line-numbering error of MS (but also other useful improvements, recognized as so!) (see my past thread https://musescore.org/en/node/281144 [a thread in which Mr. Sabatella received some good lessons from many other users besides me!])

I've just read through that entire thread and I agree. Staff line numbering should be bottom-up. You'll notice that even Marc agrees as well (https://musescore.org/en/node/281144#comment-889438).
But what I also agree with is that this change alone won't solve the transposition issue with less-than-5-line staves you had.

> and THE ERROR STILL PERSISTS!

From that thread, I also see no link to an issue in the tracker so that developers might pick it up and implement it. So yes, it's no surprise that this hasn't been addressed. Not that it's any consolation, but there are issues that have been outstanding for much longer and have way more impact that are not included yet either.

> And you speak me of high-standards of good professional intentions? It is clear that I have a stricter definition of what “professionalism” really means.

I don't believe I have been preaching about that to you, if I have, then that was (up until this post) not my intention. In this post however, yes, I will be calling you out on it as I have done above multiple times. For me professionalism means also staying away from attacking the person and trying to keep topics on topic instead of cross-linking to older grievances.
It also means looking past that when someone is venting their frustrations alongside some valid points.

> In fact, I know you better than many new users on this forum!

You have just now amply demonstrated you do not. And even if you somehow did, you'd be wise enough to know that my persona is entirely irrelevant to having a topic discussion on how to move forward with your suggestion to improve this software.

8. > You may have proposed me other methods of modifying a duration from the N-mode: it is however disappointing for me that you DON’T understand (or fake/simulate misunderstanding!) that it is a PROBLEM/BUG that note-duration ONE-KEY shortcuts like “4” (for eighth), “5” (for quarter) etc DON’T WORK FROM THE N-MODE! ONE-KEY IS ALWAYS BETTER THAN TWO-KEY SHORTCUTS whenever possible: that is another general principle in programming!

Please look up your definition of what a bug is.
Now as for the feature suggestion to have the duration keys also affect the highlighted input position during note entry mode, my stance is the following: It needs more in depth thought about the consequences. If after having changed the duration the input cursor would advance again, then you've just broken all the use cases in which the pitch needed correction as well and doubled their keystrokes.
However if you use Q and W (both single keystrokes in case you weren't aware) that whole problem goes away.

Then again, from your other posts, it seems that you mostly need to correct duration after the fact because you have muscle memory for different duration shortcuts than the MuseScore defaults and weren't aware you could just change them.. I trust that now that you are aware, you'd find yourself much less in a state where you have to correct errors.

9. > As programmers, you should learn more from mathematics and mathematicians regarding generalized functions which are the equivalent of a generalized algorithm in (music) programming. Evolution in mathematics means generalizing (or extending) over and over again various functions, theorems etc: that is what evolution should mean in programming too. That is why I’ve proposed you two generalized “link” and “cross-staff” tools in MS.

As a programmer that majored in mathematics in high school and was raised by a mathematician (there, some more personal comparison facts for you) I'm possibly aware of some mathematical approaches. However I'm also enough of a programmer to understand that generalization is not the holy grail. It has its place and if the model calls for it, we should indeed use it.
So far the model simply doesn't call for it.

10. > Let me give you a more specific personal example from mathematics (from number theory to be more specific) on the power and importance of generalizations. [...]

Congratulation on your paper. Now can we get back to the actual topic?

> Why should I expect more from you? I realize now that I shouldn’t have expected you to understand many ideas of mine, simply because visionary music programmers are very rare, like visionary mathematicians or MDs are too.

Agreed. You shouldn't expect others to have your background and mindset when posting your ideas. Then again, you might consider actually explaining them when asked for clarification on them.
And for such a purpose, keeping a single thread on topic and discussion a single feature/idea can go a long way.

11. > As you may see from my answer, professionalism means also building rigorous and well-argumented answers, not just to throw low-value one-line answers like Mr. Jojo does, like an “air bomber” (maybe he’ll change his MS Forum nickname to this one)! I expect more rigor, correctness and broadness from you: it is obviously clear that my expectations are too high for the moment! Maybe the future will teach you the GREAT lessons named “RIGOUR” and “ETHICS” (so that to NOT intentionally omit giving replies on relevant reported bugs)!

I have to disagree there. Yes, Jojo's answers can be (too) short, but they're always to the point. Being rigorous or well-argumented isn't the same as being elaborate.
You wish to call me out on my correctness? Go ahead. I'll even do you the honor of admitting where I was incorrect if you can so point it out.

12. > You may put this message to your saved messages collection: I’m sure no one on this forum (in the history of MS) dedicated you so much of his/her time and patience with such (undeserved!) generosity as I did.

There is no such thing as a saved messages collection. This is a forum on the internet, and as long as it lives all messages remain public for all to see. You also overestimate your own time and patience compared to other users.

> As years will pass, you’ll surely (I hope!) remember some of my lessons received in this last message of mine to you. You may consider yourself as one of my “adult intellectual patients”. You’re however lucky because I write text on the keyboard at the same speed as I speak it and didn’t take too long to write you this last message.

It must be my narrow mind, but I have not yet experienced your response as a valuable lesson. Or perhaps I have; the lesson being that staying on topic is rather hard.

13. > PS. See my site: www.dragoii.com/pms (I’ve just created this site today; you don’t want to know how many teaks I had to do so that to surpass the flagrant chronic problem/bug of MS to NOT correctly numbering staff-lines!

I'm not surprised that using a non-standard notation system requires some tweaks at all. I'm more surprised that you needed "many" of them as from the resulting images I'd expect there to be rather few involved.
Then again, I am quite proficient in how MuseScore does things.

> See and wonder: https://musescore.org/en/node/281144; I’m quite sick of that thread and I’m now sorry for the time spent there with NO result! Mr. Sabatella SURELY didn’t deserve my valuable time then, but also the valuable time of the others who agreed with me NOT with him at that time!)

To be sick and tired of that thread you do sure like to point it out in a non-related topic. I'm also surprised that you found your time there wasted looking at the facts again:
You raised 4 main points. 3 of them were acknowledged as bugs in the first reply, of which 2 have been fixed. We've gone over the line number already in this thread, but as you can read there, obviously your time did have an effect as Marc agreed that it can make sense to change the numbering. For the last item you were given a two click workaround.

In conclusion

I don't know you, nor will I claim to have figured you out at all. But so far (perhaps due to the language barrier as well) you've given the impression of feeling superior to justify your requests as the only correct way to handle something with a complete lack of trying to understand the product you're attempting to change.

Open mindedness goes both ways.

I'm really only interested in TAB and it is a pain having to exit note entry mode and click a toolbar button to fix a duration. Q and W would be a good start but numbers cannot be used as they would, rightly, get interpreted as fret numbers. Maybe other letters could be used. I am not well enough informed on how this could impact other use cases but I would like to achieve mouse-free note entry if possible and stay in note entry mode for simple corrections. I understand that the majority use case/s need to take priority and it's not a major gripe, just a "would be nice to have".

In notation I have no idea as I never enter any but the OP seems to indicate this same issue but with notation.