I probably going to leave it like this because might hinder the movement if I extend it all the way back to the base foot. And if I make the hole bigger it might look weird (in my mind).
Maybe if I use pla plates instead of runers the inner frame would be better but the whole thing is done now so I won't change it.
RE: Devil Gundam: Progress on Toe's Inner Frame [Leg Modification - Part 120]