"Mouse move tolerance" doesn't work as it is meant to be?

[knoajp]

I use both Right_Links_WE(RL) and Gesturefy. Both with right clicks.
I don't remember when it started, but RL unintendedly opens tabs on the mouseup event of my mouse gestures.
I want RL to only open tabs when the mousedown and the mouseup fire within the Mouse move tolerance preference. Doesn't the preference mean for this purpose?

Firefox 118.0 (latest)
Right_Links_WE 0.5b12 (latest)
Gesturefy 3.2.8 (latest)
Mac 10.15.7 (old ;-)