The stability criterion, spec §9.3 ruling 3: "the ROOM tab asks for the next position until the
modes stop moving... and says how many it used." A caller re-runs roomModesOf with one
more position appended and asks whether the confirmed set is the SAME set (same count, every
frequency matched within one bin) — if so, the last position added nothing and the sweep can
stop; two is the floor, never the ceiling, so this is never consulted below
ROOM_MODE_MIN_POSITIONS.
The stability criterion, spec §9.3 ruling 3: "the ROOM tab asks for the next position until the modes stop moving... and says how many it used." A caller re-runs roomModesOf with one more position appended and asks whether the confirmed set is the SAME set (same count, every frequency matched within one bin) — if so, the last position added nothing and the sweep can stop; two is the floor, never the ceiling, so this is never consulted below ROOM_MODE_MIN_POSITIONS.