MusicXML leadsheet import

I'm working on a workflow to import jazz leadsheets into MuseScore, using iReal Pro as a source. The idea is to convert iReal Pro songs into MusicXML files, which can then be opened by a number of apps, including MuseScore. In MuseScore, one would add the song's main melody, and get a decent playback of the songs in a completely open environment (since the iReal Pro leadsheets are publicly available).

I'm running into a number of issues which I will list here, and I'd be happy to get feedback and to open actual bug reports / feature requests.

1. No chord (N.C.)
   In MusicXML, a harmony/kind value of none determines that no chord should be played. When MuseScore finds a none chord in MusicXML, it still converts it to a playable chord (noting that the root-step needs to be specified, as per the MusicXML specification). Interestingly, when the sheet is edited in MuseScore to explicitly write a chord as "N.C.", then exported to MusicXML, the N.C. chord is correctly exported as none. This seems to indicate an asymmetry between MusicXML import and export.

2. Unplayed slash notes
   Typically, chords are notated on the staff using slash noteheads whose function is to indicate the chord's duration (but these dummy notes are not meant to be played). In MuseScore, it is possible to specify that a note should not be played, but how to indicate this in MusicXML in a way that MuseScore can understand? note/unpitched seems to convey this meaning. In this case too, MuseScore ignores unpitched notes and imports them as pitched instead. Also, MuseScore does not export the "do not play" directive to MusicXML.

Attached is a zip file to illustrate the issues here:
- Moanin' (manual editing).musicxml contains a desired syntax that would be understood by MuseScore to create a playable leadsheet.
- Moanin'.mscz contains the desired result of importing the MusicXML above
- Moanin' (MuseScore).musicxml contains the result of exporting the MuseScore sheet above (in 3.5.2)

Thanks,
Karim