I agree with Carla about getting rid of the dry food so that Buster doesn’t get into it.
If you can’t get your civvie on board with wet then look into a dry food like Young Again it less than 1 % carb. You can only get it online. It’s a bit pricey but an average cat only eats 1/3 cup a day so you have to favor that into the cost. It is very protein dense so that is why so like a day is needed.
So it Buster gets into it, it isn’t so bad.
I crushed a few pieces of it and sprinkled on top of the wet food to get my boys off the dry stuff.