When I was in high school I had a friend who was really into that kind of stuff. I was interested in it too, but even then I knew it was never going to offer a career path sadly. You don’t need to be a genius to do it though as Louis Rossmann has proved on Youtube (all he does is diagnose and fix circuits, not modify them to do other functions). Although to do what poita did from scratch you’d need a lot of knowledge about how every aspect of the electronics involved in it worked.
It’s a shame that Pioneer and others didn’t make their high-end players NTSC & PAL compatible in the first place really.