I know some people say that aluminium frames don’t like being reheated during the powder coating process but should I be genuinely concerned about this or is it just anecdotal?

And should I be more concerned if its an especially lightweight frame?

Most aluminium frames are heat treated, the problem is when the powdercoater just bungs it in with other stuff at a temp that is too hot. Get it powdercoated with a powdercoater that knows what he is doing with ally bike frames.

Top end of powder coating overlaps the bottom end of heat treatment for aluminum alloys.

High grade aluminium alloys are far more fussy about precise heat treatment temperatures than monkey metal grades.

I was going to use someone reputable like Triple S?

I assume they will be aware of this or am I chancing it regardless of the quality of the actual finish?