Oh, now it’s starting to get fun & exciting. How I love the Mechelmta of Torah!
You actually ask good questions and now I can use Lomdus to answer them. Let’s try Cheftza & Gavra. The Issur of Havara would be on the Cheftza and the Chesoron (blind man or blanket that you put there) would be on the Gavra. So since the Cheftza didn’t change -it would be Ossur! On the other hand, a crock pot is made with the heating element covered. I’ve never seen one made differently. So the Chesoron would be on the Cheftza and it would be Mutter!