Oxy acetylene on plumbing is really where higher heat is needed, the original brazing done in Silver.

oxy propane is the next down, then Mapp gas, then propane ( for use with lead/tin soldier )

access and heat protection of adjacent parts is of course a concern.

my plumber decades ago used Mapp gas and silver. He also had a water spray bottle incase he ignited the wood studs, which he did twice.