Interesting to see a selection of different app beneficiaries in one place seems that they're all very similar now, with a few minor exceptions.
Utopian's beneficiary is actually optional, however, if you choose to add the beneficiary your reward is increased to help cover the cost.
it seems to be no limit of beneficiaries’ count.
I think the max you can have is actually 8, but I think that can be adjusted by the witnesses, I'm sure I read that somewhere, however, can't seem to find the source.