lower control arm 1972 Duster

It's a fair question. One thing I believed overlooked here, is most hard braking is or should be done in a straight line. In that case any suspension issues caused by lack of strut control of the LCA are fairly symmetrical with a proper set-up and do not affect ultimate braking or stability. meaning, it matters little in a straight line. Now of course as any turning occurs/increases while braking that outcome can change.

Understand on your nanosecond of movement, nobody has defined when that movement might ever occur/occurs, except maybe when backing out of the driveway or sliding backwards in a skid at 50mph.
This of course is assuming the front wheels always have some rolling/aero/braking/etc drag on them which keeps the dreaded slop always closed to one side. There are no normal forces present acting the other direction. The slop here does not define a loose rattling condition, the LCA pivot point is ALWAYS under load.

Your original question asking for an explanation on a "bound up situation" is worthy and also shared by me.