MIDI export of Open Hi-Hat broken when using Musesounds drumkit

[mdeluca70]

Issue type

Import/export issue

Description with steps to reproduce

1a. Open new score, add "Large Drum Kit" as instrument. Note that this defaults to "MS Basic" in the mixer.
1b. Add notes for Closed and Open Hi-Hat
1c. Export as a MIDI file.
1d. Note that "Closed Hi-Hat" appears as MIDI note 42, and "Open Hi-Hat" as MIDI note 46. This is expected behavior.

2a. Open new score, add "Large Drum Kit" as instrument, then change instrument in the mixer to "Musesounds Drumkit"
2b. Add notes for Closed Hi-hat, and then change some of them to Open Hi-Hat by adding the "open" articulation symbol
2c. Export as MIDI file
2d. Note that all notes (those for both open and closed) appear as MIDI note 42

Supporting files, videos and screenshots

Musesounds vs MS Basic Drumkit.zip

What is the latest version of MuseScore Studio where this issue is present?

OS: Windows 11 Version 2009 or later, Arch.: x86_64, MuseScore Studio version (64-bit): 4.4.1-242490810, revision: github-musescore-musescore-0b3dd00

Regression

Yes, this used to work in a previous version of MuseScore 4.x

Operating system

Win 11

Additional context

This issue currently only appears when using the Drum Kit in Musesounds Percussion (so I have marked this as working in earlier versions, when this option was not available). What is not clear is whether this is an artifact of the move to a new percussion system (started in v4.4, expected to be completed in v4.5), with the new code being added in 4.5 providing an interface to address this issue. But as currently configured, drum export for open / closed hi-hat is broken when using the Musesounds drumkit.

Checklist

• This report follows the guidelines for reporting bugs and issues
• I have verified that this issue has not been logged before, by searching the issue tracker for similar issues
• I have attached all requested files and information to this report
• I have attempted to identify the root problem as concisely as possible, and have used minimal reproducible examples where possible

[mdeluca70]

Additional discussion of this issue at https://musescore.org/en/4.4.2#comment-1258646