New method suggestion for setting note lengths while inputting music

I brought this up in a forum about a different FR, but I have done some work to clarify it, and am posting it as its own request.

I have always been annoyed that entering music into notation programs does not follow the natural way that music is performed. As an improviser I wish that writing a score, at least in the earliest stages could be more like improvising.

A few notes about what that entails:
If improvising a melody (as applies to any mostly monophonic instrument) there is an order to things.

When I start a note, I do not know how long it is. Its length is determined by when I RELEASE it. When I release it, only one of two things happen: I start a new note, or I rest. In between these two events, I as a musician need to do one other thing: I need to KEEP TIME. And it is through this process of keeping time, or counting, that I determine note duration as a musician.

So, if I play a melody instrument, and I have a passage that has a 'pulse' of an eighth note, (meaning it is mostly eighth notes, with some quarter and half notes, and similar types of rests) every eighth note-sized chunk of time can be represented one of three ways: as a note start, as a rest, or as a continuation of an existing note.

This means that if I had a key command that would increase the length of the most recently entered note by 1/8th note I could type in the passage as a series of 8th notes IN RHYTHM (until such time as there is a triplet or a sixteenth note, of course.) If you are not a drummer or jazz musician, it might not be obvious how intuitive and fast that could be. As someone who is both, I can assure you that conceptualizing a melody as a series of 8th-note pulses of the three types of keystroke above is in fact a musical skill many of us have. And this means fairly long stretches of notation could be entered IN REAL TIME, especially if you have a midi keyboard to enter the pitches.

It has taken me a long time to arrive at this (and it took the musescore forum to show me I actually wasn't even the first.) I started out being impossibly annoyed by the necessity to end a note before I begin it, in conventional notation programs. Then I discovered noteflight, which allows you to change the duration of a note after you enter it, which is more intuitive, as performers start notes before they end them.

MuseScore is the only other software I've found with that capability, thanks to the 'double and half selected note length' commands, so I'm motivated to stick with it. It's a clear step in the right direction. However, you are only changing the TYPE of note displayed, not specifically its length, so you can't get, for instance, a note 5 1/2 beats long, and the physical act of setting the note length doesn't have any musical performance analogue. Though an improvment, this is still treating notes as if they have no particular meaning off the page. It concerns itself with the SYMBOLS that need to be created, rather than the ACTIVITY those symbols represent.

The ACTIVITY of playing a whole note tied to a half note tied to an 8th note is STARTING a note, and HOLDING that note for 6 1/2 beats. In notation, by contrast, you create three notes of different lengths and connect them together. So notation commands are:
select whole note
input pitch
select half note
input pitch
tie them together
select eighth note
input pitch
tie them together

Whereas my sequence is:
select 8th note
input pitch
Count & 2 & 3 & 4 & 5 & 6 & in eighth notes with the 'increase note length' key.

The former act is very analogous to the act of writing out music. The latter is far more analogous to playing it.

Here is how the input of a melody with an 8th note pulse can be accomplished with a set of keystrokes that themselves can be represented as a string of 8th notes:

In this example I've represented the '0' keycommand with an X, and the increaseNoteLength command with an X in a circle notehead.

I put this suggestion to the author of the duration editor, and he helped me craft the following user story for it:

(1) Feature request:
AS a score editor
I would like to select a note, a base duration (e.g. eighth note-which probably would just be the duration currently set for new note creation) and press a button (called "the button" in the remaining of this analysis.)
I would like that, when I press this button, the duration of the selected note (which for the intended purpose of this feature will usually be the previously entered note) will be incremented by the base duration, and the note will remain selected, so that it can be incremented again by the same amount using the same button
IN ORDER TO enter the note duration on a felt basis (opposed to on an upfront known basis), while simultaneously getting immediate visual confirmation of the note length increase and any side-effects thereof.

(2) Tying notes
AS a score editor
I would like that new duration be correctly represented as notation by creating and tying to new notes as needed, even across multiple bar lines, and that the most recently created of these notes remain selected, in conformance with (1) above,
IN ORDER TO allow the length of the note to be correctly incremented indefinitely.

(3) Tuplets
AS a score editor
I would like that, if some kind of tuplet is selected for the base duration, the button would increase the length of the note by the base duration in the same way. If the base duration is an 8th note triplet, and the selected note is also an eighth note triplet (which it would typically, but not always, be) the note would be increased by the length of an 8th note triplet, giving a quarter note in an eighth note triplet bracket. If I press the button again, the selected note would change to a quarter note. Press again, and it would become a quarter note tied to an eighth note triplet, and the second of these notes would be selected.

(4) Replacing existing notes
I accept that as I am entering notes via this method as in the program in general, I risk removing existing notes, so
AS a score editor
I would like that if the increased note-length results in the selected note occupying the position of an existing note, the existing note would be removed.

Thanks for listening!