Why do you have the bypass opened when the cat is still active? It's sounds like there is still some fuel for it to eat. I'm not sure why you want to waste potential heat up the pipe. Personally I don't open the bypass until I'm ready to reload. Where the did advice come from not to open the door when the cat is still too active? I'll open my door at any point as long as I bypass the cat for a few minutes first. If I waited for the cat to be room temperature before opening the door I'd never be able to time loading the stove. This is why I like this thread you get to see how others have success running their stove.