I havent tryed it but if you change to a filter that has less air resistance then yes i think you also have to put a bigger jet in.
Because more air needs more fuel.
I guess you could just leave the original airbox on the scooter if you dont mind.
Or you could run the hoses so that they point downwards and away from the rearwheel so that dirt dont come up inside them.
The hoses lets the engine and gear breath so you dont want to close them of. I guess you could put the hoses inside a sponge.