I would love a feature to be able to pin certain instrument to be the only sound to audition the incoming midi notes from my controller.
This way I could hear my favourite piano sound while composing, but then do not worry where I have inputted notes recently and if that instrument has the range or timbre to be able to sound whatever I am fiddling with on the keyboard.
When not using a separate program there is significant overhead in selecting desired instrument to input notes, inputting them, selecting piano and going in and out of input mode to get the desired sound, and then getting back to the desired instrument to actually input notes, all for one or couple of notes, over and over again.
Sometimes the desired sound is piano, sometimes it is cello, sometimes a bass clarinet.
My workaround is having a separate program open at all times, but having a native solution would save me a lot of time.
Have a nice day,