Yes: the pipe inside the valvecover is sealed,. but in my setup, there is no return

(you can see a pipe yes, on the metal -intake, that 'looks' like a blow-off or return-thingy, but its just a dead end

I used original Polo 2 G40 hoses and tubing, which are rare. Didn't want to cut it up in pieces, and I do need the breather (from crank-housing), to 'oil/lubricate' the G-chargers internals.. (which you can see towards the rear).
it is 'lean' as in: It could cope with some more fuel, but there just isn't a possibility to give it more fuel without a higher idle. Governor needs to be modded (slightly): when I floor it at idle, it doesn't smoke - at all - : Not to say that it has to smoke, but it just isn't - at all -
Anyways: love the torque; it's just there. From 1500 to 4000 rpm: all the way. No need to rev it at all..