Cams used to be welded and reground all the time (probably still are). As a kid in the late 80s I drove a truck for an auto parts place and went to a local engine rebuilder weekly. You can watch them do it, all day. It's a thing. Not even sure why this is being questioned.
I get the feeling if he say it was a bad idea, someone would call him out by saying "But older metal is better, weld and regrind!"
I'm sure it is a thing but your average garage mechanic isn't going to do it they will order a new one and R&R it heck even today they may just do a straight engine swap because a reman engine has a warranty like said cost effective.
