This is usefull because i have for a example a multiinstrument with diffrent piano or guitar.... sounds i like. because i need only 1 piano in a song i mute the other pianos in multiinsttrument that are not so good for this song. but when set the track to solo all instrument on multiinstruments are set to solo. this mean all pianos play.
I see no reason wy the solo button of a track change the solo mute settings of a multi instrument. it make only this problems. when i change mute on the track it change nothing in the multiinstrument mute and solo settings. same should be when solo a track too