Off the top of my head, I'd say try reversing the second and third conditions in the TargetSet function.
It worked. Thx. I understand now that logic In c2 is "from all objects with variable N pick nearest". Bit odd to me, but thats fine.
But Mirror function only worked partially - only several instances mirrored, and rest stayed the same! Top function is called on click of mouse : on click, for each IN FAMILY, call function. Seams like there is not enough tick to do all. I don't get it.
EDIT@ To mirror, I've added "Pick by unique UID" and it worked. But it's weird that I don't need to do any picking before, if objects where picked in previous events. ANy idea why? THX!