oh that depends on the catgirl machine model you have
there's competing branches of the tech that's actually doing the TFing:
- one of them just picks an arbitrary molecule inside the machine and spreads the catgirling outward from there, so a dangling leg will totally get caught by it and it won't matter if the rest of the person is inside the machine or not, they'll get the full effect
- one of them is an all-or-nothing deal that requires the door to be closed and all body parts to be in the machine or else it doesn't work at all, so for that one your dangly-leggy person wouldn't be bothered at all
- there might be a third one that might lead to like... partial catgirlification of just the one limb that's in there? but that's way over my head at that point
I forget how you tell which model you have, but it should be pretty easy to figure out through trial and error. good luck!
