It's a hard call..
Personally, (On one hand) If I didn't have the spare tracks to experiment and dedicate to the the crowd mics, then I likely wouldn't do it, I'd get the best music tracked first and foremost.
But on the other hand If it was an informal recording that wasn't the end of the world I might try it for future reference.
Maybe you can track the crowd on a seperate machine and add the actual applause after each song into place at your level choice at mixdown.
That MIGHT at least give you some fexibilty and an out in case the performance's are great, but there's only three bums, a wino and a hooker there clapping. By that I mean, it might seem silly and detract from the vibe of an otherwise cool recording if for some reason you're stuck with halfbaked applause irreversibly in the mix.
ALSO in SOME of the live recordings I've heard it kind of seems like there's a 10 to 3 ratio or something... I mean 10 people MIGHT sound like 3 people applauding when it's on tape, so unless there is a pretty wild audience it MIGHT come across "weird" and IMO you don't want to paint yourself into that corner.
(If you can be prepared and comfortable enough to mix it in or abort it once you see the crowd, then of course you'll be in the best possible position.)
I'm certain someone here can give you the lowdown.
I hope you'll follow up and let us know how it turns out.