I run my slipper at 6.5mm. Still on all kit gears, run every week since Christmas.
Get some under-Lipo weight added. I've been running 40g under each Lipo, and another 10g in each triangle. Just last night been given some lead flashing weights to go under each Lipo, 62g each side, so can remove all the other, and run these slim lead weights. Back end is super planted now, mega rear grip.