Actually, and displaying blissful ignorance again, I imagine that you wouldn't be agonising over use of glorified door-closers instead of something more conventional for damping if class rules didn't restrict.
Must the OE dampers be in use or merely present..?
I'm also good at spending someone else's money, so an upper link that attached to the lever-arm OE damper body at the OE damper location is attractive but presumably also out. In this class.
What about locations and lever lengths, though? If bump steer is genuinely what's going on rather than any other characteristics then equalisation of link length would seem obvious. So that's also out too, in this class.
If all that's true then the modified or adjustable kingpin trunnions must also be beyond the pale; but, they seem not to be that. So, there's a grey area.
Ah, I like those!
There's a fascinating you-tube log of two fellas in Shropshire (OK, in England) building an A-series Mini but with Celica GT4 powertrain and running gear. Yes, that's everything fabricated new except the roof, more or less.
Since there's complete bastardisation of the GT4 McP struts &c into all-new body structure and connived into a space that's half the size of the original Celica, geometry is an opportunity. There's a good illustration of a not-too-hard method to see bump steer, etc. Take a look at 'Project Binky' here;
http://www.badobsessionmotorsport.co.uk/project-binky-episode-11/ That way, there'll be data.
F