Add more rubber to the rear, and lower the rear tire pressure if you want to increase the grip.
I have max camber with the stock suspension (no camber plates).
In my case around -1.5 both front and rear.
0.1 toe-out front and 0.1 toe-in rear.
265/18 front tires and 285/18 rear tires (Toyo 888).
Not the perfect set-up, but the set-up I started this season with.
No use spending money on coilovers until I have tried the stock suspension out thoroughly IMHO.
The car is still a bit tail happy when driving aggressively on the track, but with soft hands it works well.
An interesting thread.
I'll keep on eye on this thread to see if more valuable input will come from people who actually drive their 1M on the track.
Good set-up input is worth more than lots of aftermarket products