That was an incredibly helpful post, David - thank you! I've been using the XY setting but am going to try the MS setting with the two side mics set to zero input and see how that sounds.
I think that with a little work I might be able to just record directly to audacity, which would be nice, as long as I can limit the amount of background noise.
One problem I'm having is that when I set the frequency to 48 kHz, as you suggested (this is with settings adjusted both in audacity and on the zoom), when the recording is played back, it is lower in frequency than when I recorded and it skips… any tips on this one?
ETA: when I set everything to 41 kHz it sounds just the same as when I recorded and does not skip - something about moving up to 48 is not working..