The magwell and grip are the biggest handicaps to the pistol out of the box, lots of guys are sculpting the grip and doing the carbide overlay which is a big improvement but once you remove the add on mag funnel to be legal there isnt a whole lot you can do with a dremel to make it more forgiving.
I see wilson is offering tungsten inserts for their grip module which may be an alternative to consider, the wilson module has a much more forgiving magwell as it comes and more can be done to open it up with just some light work on the sides.