Even roller mode will cut power to stop the wheels spinning. I need to have a play in a deserted car park. I am now running sport mode and DSC 'off'.
I suspect that the car is just trying to stop the wheels spinning.
The big sway bar definitely helps with putting power down out of corners, but it's a real hindrance on long sweepers. The faster I go, the more sideways I am, even with power. Maybe it is OK and I just need to get used to it. It is good for really tight courses, but too much for me on the others. My first event with it was a fast course and my rear tyres were scrubbed much more than the fronts. 2nd event was really tight and I did well. 3rd event was banked and crazy fast, I was not wanting to push it, the rears wore similarly to the fronts. I'm going to try and make an adjustable linkage to give me a big range. If I fail, I will put a more subtle bar on. A solid 22 would probably be a better choice. There is a thick hollow 'Hardrace' 22, but $$$hipped from China.
A better driver could probably have a lot of fun along with rear tyre wear. But I'm not better enough, yet. ;-)
My last run at the tight course was a fun run and I deliberately threw it at the corners to get practice. My hands were a blur...
My last few events before the rear bar I was running the rear tyres only 2psi down on the fronts. That allowed rotation when I lifted or was aggressive. Balance was good, but grip was not optimal
If you fit stiffer springs, it may be a better match. ICE F56 front bars won't fit the the SE, so would currently need to be custom.
Are you within 1/2 second of M3Ps? They are crazy fast. The tight event a M3P set FTD (no karts). I merely beat most of the Miatas and all of CAM-C :-D. RWD Model 3s I sometimes beat.
If I were to leave GS:
Less roll
More tyre, much more tyre, wider wheels.
-ve camber for the front.
Better dampers.
The less roll and better dampers may be best achieved with some decent coilovers and the right bars front and rear. I think KW make some SE optimised coilovers. I'm half tempted to see if I can order a set without springs to stay in GS.