So, unless i'm mistaken, the only difference in red and yellow koni's, is that they are both adjustable for rebound only, only one set is adjustable on the car, and the other is adjustable if stripped down away from the car, which is like mine,
only mine are refurbed and grey, which is why i can't remember which way round it was? ha ha!
well, in that case i can tell you that the compression damping on the konis, is actually less than the stock, as koni race research claim to have found the 33 stock boge struts as overdamped for track use, so they designed their units accordingly, with less but fixed rate compression damping, but more notably, with a cylinder stroke and valve arrangement suited to a shortened and uprated spring,
in all honesty, your set up as far as suspension choice, should be working pretty well when compared to what i was told by the Koni Uk agents, and i'm hoping my own choice of koni's and H&R 35mm progressive springs would be working correctly too????
so, i think it points towards the spring rate is simply too soft for hard track use, causing excess body roll and weight transfer,
i don't think (???) Johnboy has any none standard rear anti-roll arrangements, or has assively overstiff springs for when he's on the road, and has always reported good handling at Spa for sure, so maybe he can shed some more light on this again
i think the fast road/track compromise is maybe just too big a gap to bridge, you may have to decide on a more bias set up, and be willing to live with the consequential sacrifice of the other?