I just don't get it .. Read loads about people using this clutch on fairly stock ish setups and it being really good. Therefore with your setup it should be amazing. I've changed it to the weakest springs and it almost entirely slips through the 1st gear without grabbing at all. Bike revs out very high and will sometimes blow lights then it'll go in to 2nd gear and and it's fine.
might just put the old cork clutch back in like what you've done.
Also, what are treats saying to you about it?