IMO we should merge all instrument settings into one Master setting for each instrument.
Either it is a sample/vsti/midi based instrument they have a basic common instrument setting.
I guess it is something for the xrni2.
Like this old mockup:
You can shrink/expand it for more options.
You can choose input (rewire midi input in this case) that will control the instrument,
and choose to dedicate the instrument to a track (like you currently can only do with vsti).
Another option is to split midi input/output into new devices you can add to
the ‘Master instrument device-chain’.
So you can add several midi inputs and outputs to each instrument.
And even into different part of the instrument if you have several layers of instruments in one.