Light cruiser remodelled to torpedo cruiser remodelled to battlecruiser remodelled to aircraft carrier. Lovely.
Considering how much trouble they had from weakened internal structure from some remodels like Taigei, CV KTKM would probably be about as stable as cardboard. (Especially since they'd have to massively expand her hull to store enough aircraft to be a real CV, and that would basically just involve cutting her in half -or even quarters- and welding more hull into the middle.)