Hey b_t ...
First of all, I don't have a clue on how to drift - though I've golded them all. It's always very much trial and error, despite getting routine of course with a single event having more and more attempts.
You know I don't use assists except ABS. Still, I know what they do, and honestly I think they don't help you in these challenges.
I'm still on the DS4 - do you use your wheel, or do you switch to the controller for drifting ?
My impression regarding the points calculation is :
Speed - the more speed, the more points
Angle - the more and the more consistent ! the angle, the more points
Line - the closer to the inside of the turn, the more points
Correct me if I'm wrong, I'm a drifting noob ...
And :
I always have to calm myself down with my steering inputs, I always want to do too much and too quick.