In my trade nothing's brazed . Tig is a really strong weld ' an inch weld should hold a tonne in weight .
Also brazing /gas welding is we're tig welding originated from .
Before tig there was gas welding it's basically a crude less refined way of tig welding.
Bronze braising/ gas welding is a strong weld I agree and the bronze it self is soft witch allows the joint to flex a little more without cracking + the fact that the weld is at least 4 times wider than most tig welds on a bike frame.
I can tig/gas weld / braise so it will be down to customer choice
But in the grand scheme of things tig is best in my opinion .
Strong
Clean
Less perpetration time
And bronze/silver solder rods are mega expensive too
Ur right about the heat though it uses less heat to braise than it does to tig weld witch is good for not putting residual stress in the metal
Other than that I can't offer any more I hope this helps
Regards leigh