Hi,
this is an idea of a new setting in Extended conditions (Erweiterte Bedingungen...):
How much space is between leftomost and rightmost finger. Would sound something like this:
mm_between_leftmost_and_reightmost_touch_y
or
mm_between_leftmost_and_reightmost_touch_x
I don´t have a magic-mouse, but maybe it could work there aswell.
Tahnks!