I doubt it. The back straps are molded to fit the frame very well. Anything underneath would definitely interfere with proper fit.I think it actually looks best without one, but I use the medium BT on my full size Glock frames, but sometimes take it off too.
I mainly feel it helps keep my firing hand thumb away from the slide stop and aids in preventing any mishaps (e.g. slide not locking back on last shot, etc.).
My question is - does anyone know if I slap on some Talon grips without any of the backstraps installed, will a backstrap fit over top of the Talons?