So, one option is to stay consistent with these additions, and go with upperCaser and lowerCaser, even if those sound a bit odd.
Why not upperCaseSetter/lowerCaseSetter? Bit longer but upper case and lower case don't have a good noun version. Personally upperCaser/lowerCaser sound really bad to me, though I like the idea of keeping it a noun because that matches every thing else.
