Removing unwanted instrument changes in the Mixer

I'm trying to create a master pipe organ template (and updates to instruments.xml) using the Jeux14.sf2 pipe organ sound font. One issue that I had was how to remove multiple Mixer instrument changes per staff - for instance, my Swell rank may have had (in an incoming file that used the Violin patches) 3 instrument changes (in the mixer) and I wanted to remove these so I just had one mixer instrument per staff. My objective is to take a MuseScore file that might have a few instrument changes for a manual, and reset them back to just one at least at the first time I'm editing the score.

I realise the first thing to do is to remove any instrument change directives in the score, and I also removed all dynamics from a score too. However, when re-opening the MuseScore file, the multiple mixer instrument changes were still there. A couple of forum posts mention this issue (getting rid of multiple instruments per stave in the mixer), but I was still unable to get rid of these changes based on those instructions. Despite (what I thought was) no instrument changes, or dynamic changes for that matter, the incoming score still retained them in the mixer. I now understand these instrument changes remain in the mixer until you update 'Change Instrument' to an instrument that does not have multiple patch variations based on dynamics (eg. Violin has pizzicato etc. - 3 or 4 possible patches and these mixer entries will always appear at least until you change instruments for the staff, even if you have no Instrument Changes or Dynamic changes).

I think I've worked out how to deal with this situation, but was wondering if anyone could correct my logic here (or have I worked it out? I'm not that confident!). Here are the steps I took with the instruments.xml file:

1. Added a Genre element (I called it "pipeorgan"). This seems to be just a selection criteria.
2. Within the InstrumentGroup tag, id="keyboards", I added a new Instrument called id="pipe-organ-jeux". I gave it a name "Pipe Organ Jeux Rank" and changed longName and other tags accordingly.
3. In this instrument, I made staves=1 and added it to the genre "pipeorgan".

After restarting MuseScore, I can now change Stave/Part Properties, and set the Change Instrument value to "Pipe Organ Jeux Rank". Because this has just one stave, and no Channel settings, my score now just has the single mixer instrument choice per stave - which is what I wanted.

Have I understood the use of the instruments.xml file and the choice of an instrument correctly with the changes above when you have a goal of having just one instrument per staff in the mixer window?

I think there are probably some other interesting things you can do with the instruments.xml file when using MuseScore for pipe organs with multiple ranks, and I'll keep investigating this - for now, I just want to know if the edits I've made to instruments.xml are appropriate when trying to get a pipe organ score back to having a single instrument per stave.

ps.I was experimenting with Marc Sabatello's 'Fugue #1' (an impressive work, but that's another topic!), which comes with MuseScore 3. This had multiple mixer instruments (even after I'd removed all the dynamics), but I understand this is because the original score used instruments like Violins, which have multiple dynamics (and consequently instruments eg. change instrument patch to pizzicato). I was able to trace these back to the Channel program value=xx settings for the instrument. Hopefully down the track I can modify instruments.xml in a similar way to insert the various pipe organ ranks. If I can get my head around the changes to instruments.xml for easily using pipe organ SoundFonts, I may write another tutorial on this too - but need to be sure I'm technically across the capabilities of this interesting file first!