there really is no point in using any more than one reverb,
unless it's for a special effect.
the idea is to create a soundscape that gives the impression of 'space' and 'room'....
using any more than one reverb, to me, just does not make sense.
now, that said, i routinely setup two reverbs.
LOL
i like a certain 'room' effect on drums, if i use dry samples for example, and i'll have a reverb dedicated to just drums.
then, a master 'verb' that gives me the room or space sound i want across the entire recording.
but yes,
setting up a single instance,
then sending the levels from the individual tracks via SENDS, lets you not only set the amount of reverb you want,
but also lets you pan the reverb (assuming you are using a mono instance),
which is a trick i learned from steven wilson, who learned it from robert fripp.... that if you pan your effect to match the pan of your track, you can separate out reverbs even more that way.
and i'll often pan a track hard right (like a conga) and pan the reverb the opposite side.
works for guitars and vox.