I'm also a plate hog, however, I always contact my partners for the upcoming week and discuss it with them well in advance of each game.
I always ask the question in this way: "Do you want me to do the plate?" I usually get 'sure, you go ahead' answer, so I'm happy with that.
If I sense any hesitation on their part in response to the question, I simply state that I'd prefer to work the dish. If it's a double header, I typically want to do the first plate, then I'll take the field.
My association is big on working the dish, and grabbing as many as I can behind the plate has served me well in evals, upper division conference games, state playoffs assignments, etc.