Laurens I agree with you with the blockley tread pattern, at first glance they appear to ‘wall’ the water within the tyre & not allow it to dissipate excess through the tread pattern. They certainly make the M3W handle better in dry conditions and any damp let alone wet conditions enable the backend to step out of line through either throttle or steering (generally recoverable through either throttle or steering too) and it’s skittishness that makes the M3W exactly what we love - exciting sheer driving.
Always bear in mind how you would ride a motorcycle in the wet rather than drive a car and you won’t go far wrong.