1) I employed “Change divisi” to turn a double bass ensemble staff into a solo staff. Later, I double-clicked the signpost to change it to two solo instruments, and it broke the bracketing:
Note that the bracketing is screwed up only in Full Score view. If I switch to the part, the bracketing correctly envelops both staves:
2) Although I set the notes of the staff to “Up-stem voice 2” in the Write tab, they are designated “Up-stem voice 3” in the Play tab. Similarly, if I set them to “Up-stem voice 1” in the Write tab, they are “Up-stem voice 2” in the Play tab. (Dorico might be reassigning the voices of the upper staff accordingly, I don’t know.)
3) Try as I might, I am unable to assign the lower staff to a VST. I have tried setting it to a new up-stem voice, I have tried setting it to a new down-stem voice, I have tried making the change in the current flow and in all flows in the Play tab… nothing works. Whenever I select the VST, it snaps to “—”. The upper staff is fine, I can assign the proper VST and channel and it plays perfectly.