I have no skin in this game so to speak, however this statement comes up a lot and drives my curiosity! Who is going to design airframes specifically for AMA Sportsman thru Masters? Would it not make sense for a producer of a pattern kit, to design it to be able to be legal worldwide for a larger sales base? In that case many would fly it under FAI rules which remain at 5kg, so it would make sense to design for that rule set...no?

Changing FAI weight rules will for sure impact airplane designs, but I dont see how changing AMA rules would have any impact on airframe designs, outside of those that have the motivation and skill to design and build their own.

Just some thoughts from a nearby outsider