I have seen John Ryan's last about 15 minutes in one session,where different instruments took the diddley bit between the loud Ds, who plays next being determined by the session host. OK if you don't take it too seriously: I thought is was a big laugh.
Same with Johnny McIljohn's as mentioned by Jack Campin, and at Nigel Gatherer's sessions. It's probably only one tune per session anyway: I can cope with that.

It is also quite commonplace in Bluegrass sessions to invite certain instruments in turn to lead the tune.

Mostly here, tunes get played just twice before moving on to the next tune in the set, because most folk have learned all the same tunes. That is unless, in the fairly rare event, of someone introducing a new tune (which doesn't always go down well with some of the "everyone must be able to play everything that everyone knows" brigade.) In this case you might play it 3 times to give people more chance of picking it up, while the brigadiers go to the bar or the toilet.
I do find some of the sessions are a bit samey, in terms of content, but worse than that, over-familiarity can lead to "automatic pilot" with loss of musicality and excessive speed. It's refreshing to go elsewhere, even a few miles down the road, where the "standards" will be a completely different set of tunes.

Other than that, I'd say there's more scope or call for arrangements if playing more privately with a small group of friends, and indeed we do just that when planning a performance gig.