Make staff properties "change instrument" and "change channel" available in plugin API.

Please consider making it possible to change instruments and midi channels via the plugin platform. I have several educational plugin projects in mind that require such a feature. For example, with the help of a programmer, I want to develop a rhythmic solfege TakaDiMI and movable chromatic solfege (e.g., Do Di Re Ri Mi Fa Fi So La Li Ti, ascending sharps) plugins that will automatically apply the right vocalized soundfont syllable to each note value and accidentals within the measures's time and key signature. (I have already started to work on the corresponding soundfonts, albeit slowly.)

It seems the best way of approaching this is to utilize the midi change instrument/channel function, which is available in the GUI, but not through the plugin API apparently. To assign the right default chromatic solfege soundfont preset based on the key signature, the plugin needs to access the change instrument command, Likewise, to assign a non-default solfege accidental to a note (e.g., a sharp in a flat key), the plugin requires access to the midi channel command. I haven't been able to find any plugin examples or documentation to show that this is currently possible through the plugin API. Thanks, Sam