Changing engine this close to release?
Sounds like recipe to disaster.
I've written for BGIV, D:OSIII, not BGIII.
Is unreal engine even a good choice for turn based RPGs? Isn't a custom engine alike the one currently used more adapted to those specific needs?
You can adapt Unreal as you wish. Reasons for using Unreal are more on QOL, productions costs and technical side, in my opinion.