I've never seen any evidence of excessive crankcase pressure, contents of the catch can have always been very normal and only a small amount, my current setup is just 2 x 19mm hoses running to an 034 can with a filter on top (I added a small amount of baffling myself, but nothing too restrictive). Oil pressure is normal, no mixing of oil/coolant and the car runs awesome, even better with fresh plugs in it.
I'll do a compression test before I do anything else, once the tester kit gets here.
JNL say it's better to recirculate the catch can rather than VTA, JP said "Yes it's always best to recirculate as the intake vacuum helps scavenge the crankcase pressure.."