as has been said if the header breather tank is on the right side you will have no issues . If your motor is going to fill even 200ml in 2 - 4 hot laps you have alot more to worry about than oil catch cans.

Fully built 600 hp race motors that have 8500-9000+ redlines may have a slight issue of excess oil but only untill reaching operating temperature , due to larger clearences and tolerances to allow higher oil pressure and expansion of parts due to RACECAR. Thats why they have a setup like Daz has spoken about in his build with the breather and pipe running under the car .If your stock STI motor with bolt on mods is eating or bypassing oil like fuel you have other issues.

I think your setup will be fine RJ it will reduce the oil return into the engine massively the kit for emptying is more convenience .