FWIW I _think_ this is trivial for blink.  In our case pointerMovementScrolls is true if-and-only-if firesTouchEvents is true (except perhaps for the case where the touch events API is explicitly disabled - where firesTouchEvents should be false).

Yes, this looks trivial, even when the TouchEvent API would be disabled through a flag (see  crbug.com/644318 ). This is because all firesTouchEvents=true cases seem to be hardcoded to synthetic events from touches, therefore disabling TouchEvent API should automatically suppress the synthetic events hence all the firesTouchEvents=true cases.

Can I take a look at this issue? if no one works on it?