I noticed it could be usefull to have a -NONE- button just right of the VSTi selection menu in order to quickly set the VSTi instrument slot to NONE.
Actually you have to open the VSTi menu and scroll your way up to the NONE option on top of the list… while a simple button (Yes Itty, with a keyboard shortcut too) could be much faster…
Note: Yes, you can also just Righ-Click in the VSTi slot, in the instruments window (top-right) and select DELETE INSTRUMENT from the menu… but it doesn’t work right with multi-layer instruments (a “VSTi + Sample” combo) because you’re deleting the -whole- instrument.