Next time you need to run a large stick section on thin sheet, grab a can of dust buster and invert when spraying. Chill the metal after small 1-1.5" stitch bursts in areas to pull heat away from the affected zone while not actually chilling it directly(to avoid cracking). It’s pure CO2 and doesn’t contaminate the weld puddle, but comes out in concentrate onto the metal and removes heat much quicker.
Extensive trick I use in sheet metal fabrication, worked well on the sub $200K bike. Anything over 20CFM shield flow on sheet metal doesn’t draw enough heat quick enough and just wastes gas IMO, especially on vertical sheet like quarters or fenders 