honestly, i'd always do the event bonus stages (mainly that 80 stam one) unless it's the swan race....

only time I would do the swan race bonus is if i'm grinding betting materials...

those 80 stam bonus stages always seem to have the best output if not outright getting something like manyu/gold (those are best done on dailies when open) or there's bonus stages costing more stam (whaleship bonus gives a TON of medals from the highest chapter and stam cost you can clear)