I've had a bit of a debate with a group over this, but I am curious to see if there is an official answer.
If I were to have mithral full plate armor (which counts as medium for all purposes except proficiency), would it be able to be enchanted with the Bloodthirsty enchantment? For anyone not familiar with bloodthirsty, it can only be put on light or medium armor.
To me, at least RAW, it would be able to...
But at the same time it feels wrong to put that enchant on what is undoubtedly heavy armor base.