[SDPhantom]

First, you say yourself you can just use Prowl alone to end up stealthed and in Cat Form. You don't need to manually cast Cat Form.

Secondly, unexpected things can and do happen when you mash keys. When you do it with your current macro, you're sending lots of Cat Form requests and lots of Prowl ones. This wrecks havoc on toggle abilities since canceling them doesn't require the GCD. The client can do some prediction trickery, but ultimately, it's the server that decides what state you end up in. Latency is a thing we all have to deal with when it comes to client-server communication.