Tin made a video sometime ago for a circular fire-pit. It uses a small section that is not curved and then you create the curved portion as a flange. It is done in the sheet metal environment and by having the small section, it acts as the “stationary” portion for “unfolding”. That way you can make sketches on the unfolded portion vs the flat pattern. Perhaps that could be done with the pipe size of metal flange.
Here is where that video was:
Tin, do you still have that video?