[surfearth]

If you're flashing your lights as someone, why wouldn't you use the high beam? In particular, with daytime running lights on most cars, high beam flashing is the most practical tool for the job.

On my Model Y, it is a simple pull of the left steering wheel stalk to do that, the same on all other cars I've previously owned. On my prior car, flashing the non-bright lights would've required turning an awkwardly positioned dial that also controls fog lights and running lights. That is easier than the touchscreen method but still poor UX while driving.

[m463]

flashing high/low/high/low means "your high beams are on" but you can take away their night vision.

flashing on/off/on/off means "turn on your headlights" or "speed trap ahead"

[jayphen]

Flashing high/low/high/low from behind here in Austria at least means “you are annoying me but not in a way that immediately threatens my safety” (beeps are reserved for slow starters at lights or near-collisions). If going in the other direction it means cops ahead.