reboring a maf?

Hello guys

Just wondering I read from other forum that the stock gtir maf can have around 290whp but if you rebore from 50mm to 54mm it can handle around 345whp. Can anyone confirm on this? or does anyone tried this?

If that was the case, then surely the measuring filament would have to be changed?
i.e with a bigger bore it wouldn't register the correct volume of air?

why?
when you can go and get the right thing for the job being z32 or even a q45