Tempo and Feel are really subjective and can vary from time to time and group if you let them. Assuming everyone knows every song cold, then it's not a problem. But when you have less experienced players and singers, sometimes that "clock in their head" isn't well tuned yet. And with around 200 songs in rotation, it's a lot to remember. And, we try to add a new song every couple of weeks to keep the mix fresh. For all those reasons, I'd like to write this stuff down somewhere. so at rehearsal i can get out the dreaded metronome and make sure we're where we want to be. And for example, yesterday at warm up the rhythm player started playing a new song in 4/4. But it was in 6/8 beat like 2 triplets. So I could just say ("hey, it's in 6/8 beat like triplets) and immediately he knew what to do.
For now, I'm just fudging my chordpro charts by adding a line of test below the title like this:
Key: G Time Sig: 6/8 Tempo: 48, in a slow 2-beat triplet feel
I keep threatening to move to lead sheets with SMN melodies, but it would likely freak out a lot of folks! playing is fine, but when you venture closer to "reading music" it gets some people nervous.