The oil filter really shouldn't affect compresion. The spin on is used on the Mazda3 2.3L without issue so I don't see where there is any real risk that compression on the 6i would be affected by either:
a) Too little oil pressure leading to poor cylinder lubrication and piston ring sealing.
or
b) Too little oil pressure for proper lubrication leading to excessive engine wear and lower compression.
There may be a slight change (+ or -) in the oil pressure but this may be more a function of the drain-back valve in the filter cartridge which seems to work OK the Mazda 3. There is only one 'almost no oil pressure' sensor which turns on the dash light, so no finicky sensors to worry about.