@RC-Trix: Funny you mention it, I've just tried more toe-in!
I must admit, not with the way I intended to adjust rear toe, but this works pretty efficiently!
The added rear toe-in seems to help slightly, even with higher ride height and more droop (that, to my understanding, should exaggerate the weight transfer into corners that causes the sliding in the first place).
Also, I think I'm getting the hang of it now, it takes some getting used to the car. On tarmac, the last car had a very stable rear end - I suppose thanks to the wider tires - but it's loss of rear traction seemed more snappy. So overall you needed to use all the steering it had and in every once in a while it'd slide... considerably!
With this car there is less rear traction to start with, but it's less snappy. That combined with the lively front end I guess it just requires a more subtle touch to the steering
That said, of course I'll be looking to find a way to make the rear end more planted: I haven't driven it on a bumpy surface, but there it may need the extra rear bite to deliver consistent lap times.
@Phil Channon: Thanks for the advice! Do you recall how much toe-in you were usually running or how much you added?
Cool you mention the ESC set up. I found out on the last drive if I ease off the throttle instead of let go of the throttle suddenly, it stays entirely stable... as if it needs a smoother weight transfer.
The soft tires I'm definetely going for then!
I have a set of Proline M4 Calibers (4WD front and rear) and these I'll definetely glue these to compare them with M3 Caliber/M3 4-rib tires (and combinations/hybrids of the two).