I'm seriously not wanting to trash your logic or plans, but VW Group cars tend to have no issues with the factory supplied air filter design, any change will have been made only when the engine type changed, so it sounds like the chain cam driven engine had one type of air filter and the belt driven cam engine had the flat panel type filter, so it is an engine type change that will have prompted an air filter design I'd think.
I've only ever bothered to change to K&N once, and that was with a Ford maybe 1600cc cross flowed engine, and I was quite young at the time, I m now old and run an Audi S4 that still have its original Mann drum style of filter and don't feel the need to move to any other design of air filter.