Good to see that someone is interested in this, I had already been afraid that I was the only one looking into how patches could be written
I agree that the cover view as such seems pretty useless. Still, FYI: You don't need two separate patches. You can combine both into one, by providing multiple descriptors, and checking which MD5 is supplied in perform(). For example, the margins patch modifies 4 different classes (
source code).