Depends on the type of Alu and how it was made to begin with tbh-the heat from re-powdercoating after a repair would be adequate treatment for some frames depending on the composition of the alloy. A good aluminium welder/machinist would be able to give a good idea.
What is the deal. Can a guy who does aluminium Welding not just fix it though.
Or is aluminium welding less strong than welding steel?