Not really much experience with the GT4, but the laptime is decent (faster than the bop lap).

There is not much you can change on the setup side, so it's pretty much min max but drivable as you are used of me.

The setup is with TC-OFF, shouldn't really be hard to control as RBR has a lot of grip.

Try slide it through the corners as it seems the fastest way to drive it.

For setup options to make it even more stable:

Go higher on TC or Brake Bias. Increase the front roll bar or decrease the rear ride height.

You can always go higher on wing.

For question you can find me on Nils Naujoks popometer.io discord.