I don't think anyone actually uses co-op baby for combat (by duping input with joy2key, etc) This is mixing together two different things. You can spawn a co-op baby and use it in combat without duping inputs. In fights like gurdy it isn't even that hard.

If you're going to use co-op babies, then you might as well be allowed to use them throughout your run normally however you want.

The duping inputs using a program could be considered tool-assisted I guess, since that's not a function you can replicate within the game using just the game?

no the whole point is to prevent the co op combat which means that co op baby wont be able to deal dmg, if you allow to use it however you want nothing prevents you from binding keys and use it to copy your movement since it's the same as binding a controller key to the R key to reset...

if you allow to use it however you want nothing prevents you from binding keys and use it to copy your movement

I think it's easy and effective to have a rule like "You can't dupe your input, but you're allowed to use a second set of controls manually to do whatever you want." It will be obvious from watching a run whether someone dupes input or not.

It's also easy and effective to have a rule like "You can use co-op babies to do tricks but you can't use them in combat"

The question is just what people want to be doing. The most relevant opinions are the ones from players who use co-op, who will have "co-op = yes" next to their runs on the leaderboard.

Well, no one has actually been doing runs with combat co-op, so that's a big vote in itself. I'll go ahead and add the leaderboard variable with an associated rule that doesn't allow combat.