If its one spot per turn its tempting to act as solos - not as good as a duo because its more limiting on what we can do, but if a club is getting 25 turns it must be doing something right.
However, if its a busy club I would not do a 24 verse ballad nor a complete tune set - maybe just a single tune played twice. Some shanties can be over long too in those circumstances. Sympathy with novice performers who have prepared a song/tune that is too similar to what's gone before or just doesn't fit with the audience, but they don't have the choice yet to pick and choose on the night.
I always appreciate it when we go to a new club - instruments in tow - and the organisers ( residents) step down rather than doing their introductory 5 to make a space for us if time is short. Its a way to make you feel welcome.
FloraG.