Not TC6, but... every time I've had issues with tight corner entry spin-out in VTA, the biggest factor has been tires. Make sure they're cleaned, and then sauce them into submission. This is outdoor abrasive asphalt in summer, so not sure how applicable it'll be this time of year.
I've also found success in reducing rear toe-in, and moving weight forward. I'm not sure if reducing rear toe-in helped because it lengthened the rear wheelbase, or because it made less bind (Korey Harbke explained to me that inboard toe-in creates some bind, which can increase corner entry rotation). These successes may have just been compensating for poor tire prep, though. Sometimes the car would just push when the grip came up. :/
Something to keep in mind with VTA, is that the tires are much taller than normal TC tires, so if you run the chassis at 5mm, your outer hinge pins will be higher relative to where they'd be with TC tires, and the resulting angle in the lower A-Arm can take away camber gain. Also, with your outer hinge pins raised, that causes your shocks to become shorter and more angled. Also, I believe the rear tire is a bit taller than the front, and is certainly spaced wider, which messes with your wheel rate and could also mess with your roll center.
If you have some TC tires, I'd suggest putting them on, and applying a good TC baseline setup. Get an idea for how stiff the suspension feels. Look at what kind of angle is in the lower arms and how the camber links relate to that. Look at the shock lengths / angles. Press on the side of the chassis to get a feel for what the camber gain is like. Etc...
Then, put on the VTA tires, and see how much higher the ride height is. Play with all the above stuff. Then drop the ride height back to 5mm, and play with everything some more to see how it all changed.
-Mike