The bottom of the carrier being rough should only be a problem on the returning/closing stroke and not the initial rear-unlocking stroke.

If you’re have binding issues, then it could be that the cross profile of the hammer is too thick, and that either the tail of the hammer is binding on the back of the trigger (carrier wedge), or the back inside of the hammer is binding on the top of the disco hook (again carrier wedge).

Since polishing the bottom of the carrier will buy you a little more working tolerances/room, you may want to add tapering/polishing the upper edge of the hammer's firing contact pad, and taking a little metal off the hammers tail just for good measure as well (read should cover any areas that my be causing carrier/hammer wedging).