No, didn't have much time to play with it TBH.
Take a look on this old thread:
http://www.locostbuilders.co.uk/view....php?tid=97634
The consensus is that the proper fix is more caster, and one figure given is that 22-24 mm of displacement between top and bottom ball joints should do it (we have 20 mm standard). I'll try slackening the wishbone bushes and ensuring that their play is at the end of most camber angle.
One more idea to try from there -- rotating the mushroom a little bit inwards might increase the KPI angle (as the upper ball joint will have to be threaded further in to return the camber to where it was), while the mechanical trail will be reduced minimally. I'm not sure there will be space on the thread though -- the locknuts are already at the end of the thread, with just -2° camber and mushrooms straight ahead.
I reduced toe to zero, and now the car displays "a degree of self centering evident": if I rotate the wheel by 15 degrees, when driving, it springs back by some 3 or 5 degrees sometimes. This could be enough for IVA, but is nowhere near where I would consider it to have any safety effect.