Going to continue working on this other thread from here.
The best I've come up with so far is just copying the entire data.lua from Realistic Flashlight, to data-final-fixes.lua and that seems to work after setting an optional dependency on GirlCharacter with: "dependencies": ["base", "? GirlCharacter"], in an attempt to get Gear Girl to load up first.
Going to try to conditionally load parts of this mod in data.lua or data-final-fixes.lua depending on if GirlCharacter is loaded/active, but I'll need to look more into that.