Can staffs be combined/separated?

I’m coming from a barbershop music side, so normally there are 4 voices (tenor, lead, baritone, bass), but I wonder if I could enter each voice initially on a separate staff (so there would be two treble staffs and two bass staffs) and then with a simple command Dorico would combine the staffs into one treble and one bass staff. Conversely, is there a way to have Dorico separate the voices into separate staffs? This might be worthwhile also for instrumental compositions where you would have a separate staff for each instrument, but the staffs could be compined into an orchestral type score.

for the orchestral version, yes, it’s called “condensing”, and best left until the very end of your engraving/composing process (it tends to slow Dorico down a bit because the program has to recalculate spacing every time you make changes.)

for the barbershop quartet question, I think it’s a bit more touchy.
I’ve never made use of condensing with vocal music, but from others’ comments, it can be a bit problematic still.
I believe this is because of lyrics?

hopefully, someone with more experience (there are a number of forum users who write/create hymnals) will be able to give you more information.

Condensing for vocal staves currently does not work well.

It’s very easy to copy the Lead and Paste it into a new Down-stem voice on the Tenor staff; and the same with the Bass onto the Baritone. (Or, select the Bass notes, press Shift V to move them to a new down-stem voice, and then paste the Baritone into the Up-stem Voice.)

There are also Reduce and Explode functions in the Paste menu, which you can use to select two staves, copy, and paste into a new staff. However, this will put the music onto the same stem, where they have the same rhythm, which may not be what you want.

Again, it’s very easy to select the bottom notes and press V to move them to an existing second voice, or Shift V to create a new voice.