If your ABS sensors are getting pushed back a mm, does that point to something like worn wheel bearings?

 

Yeah it is something that causes the axle to slightly move radially in relation to the hub (where the ABS sensor is mounted), or the hub moves in relation to the axle. My bet is on slightly worn swivel bearings.

Could also be the sensors have lost some magnetic sensitivity at very low speed (for example the left side when making a tight left turn). The ABS system still worked fine at street speeds, only caused problems when very slow, which has led to fender benders for some forum members. Maybe the ABS software also over-reacted to the different speed of the inner and outer wheels. I suspect newer control code could deactivate ABS during this scenario, or control it better. Also might have been a contributing factor for the D2 front hub upgrade.

Note: Both the '96 and '94 acted this way, with low speed ABS activations when not needed, but fine during higher speed driving.