So ... in the end, I didn't change too much. Only aero to 5, diff power to 20 and coast to 40 and br bias to 68. I did 1:57 flat with softs. With mediums and tank half full was around 1:58:5. It's not the best result but it might be useful if someone wants to go further with the setup.
P.S. air and track temps where 19C/26C.