Never seemed to cause a problem on the many thousands of Commercial Oberndorf Mauser sporters made from 1898 to the 1940s.
They filed the hell out of the rear tangs, to produce arguably the best factory sporting rifles ever made.

Perhaps most "modern Mauser smiths", as you call them metal, struggle with the concepts of elegant austerity, preferring to make rifles that a ham-fisted customer can't bring back broken through the wrist for a warranty claim!

Check out some of Joel's work on these forums for what can still be achieved today with Mauser actions by the cognoscent gunmaker.

And not armchair speculation here, having put an awfull lot of rounds through commercial Oberndorf sporters both on the range and in the hunting field, and the first time I've ever even heard of a cocking-piece riding up the tang and jamming is in the post above!