Thanks for joining! All questions are worth asking and re-evaluating as tools and workflows change over time. I moved this question to Education.
On this brazing topic , @manzanitacycles had some good insight:
The TIG stack of dimes raw fillet look seems to be popular right now. I get it. It saves a ton of work cleaning up the fillets to make them smooth. BUT if your fillet has a thick edge beware that you’re creating potential stress risers. Several years ago a friend requested that I leave the fillets raw on his hardtail. After a year or so of riding, he took the bike off a small drop and either the top tube or the down tube (not sure which) cracked right at the fillet edge causing the whole head tube to pop off! Luckily he walked away with only some bruises. The fillet joints were perfectly intact. It was a tube failure. I can’t say for certain whether it was an imperfection in the tube or a stress riser from the fillet edge that caused the tube to crack. But I always file my fillets with a smooth transition to the tube to be safe.