If you're TIG'ing it then mitres need to be tight, if your fillet brazing it I've seen some terrifying gaps filled with brass. The issue becomes how straight the joint comes out. On a frame, that's pretty critical, on a handlebar, with 4130 that you can 'hard correct' less so. If it's just for you, and you're not too concerned with your teeth, go mental. If it's for your nan, maybe pay someone to do it!
If you're TIG'ing it then mitres need to be tight, if your fillet brazing it I've seen some terrifying gaps filled with brass. The issue becomes how straight the joint comes out. On a frame, that's pretty critical, on a handlebar, with 4130 that you can 'hard correct' less so. If it's just for you, and you're not too concerned with your teeth, go mental. If it's for your nan, maybe pay someone to do it!