MAF calibration (and therefore fueling) will be off without the exact correct intake setup. This is why the filter is REQUIRED. K&N panel filter is also often used on Romraider posted base maps because it's consistent
car to car in terms of MAF calibration. If you don't specify which filter, then someone with a FRAM is different from someone with OEM is different from someone with K&N, and MAF calibration from one K&N panel filter to another is quite consistent.
A K&N filter will not destroy your MAF. LOTS of people run the panel filters or the oiled cone filters and in my well over decade of ownership and forum participation have seen every "broken" MAF revived to work fine once it was cleaned.
The MAF may collect some oil if you over-oil your filter, but you just buy electronics parts cleaner at the car parts place and add cleaning your MAF to your preventative maintenance list for when you oil your filter. Read through this thread for tips on cleaning your MAF:
My car has run an oiled cotton style filter of one form or another for about 150k miles.
If you still don't want to run K&N filters, then you will need to scale your MAF for your chosen intake, which will require a wideband O2 sensor installed between the turbo and any cats... at this point you're essentially self-tuning, so it may not make sense to buy the map.