Greater Toronto Area
I'm a huge fan of catacombs, but I wish the stun shot didn't cause player's to miss their turn. Instead, I treat stun shots like a grapple. We place the stunning monster (or projectile) on top of the affected hero's disc. During the hero's turn, they can use their action to flick off the monster (positioning it for their allies), or wait for a friend to bump it off for them!
I've never been particularly fond of the stun mechanic, but kept it in Catacombs Third Edition for continuity with 1st/2nd edition. The timing around it can be confusing for new players. In the reprint of Catacombs Third Edition we could include tokens for the Stun shot such that it could work in a manner similar to the Bite shot. I'm seriously considering it.