I don’t think it can do that right now but I’m sure it could be implemented if everyone got on board with it. You might pose the question in the development thread where TK and others are active and more likely to see: Anduril ... 2?
That said, I think you might be best served by going a more traditional route with standard road emergency items - and double check the legality to begin with of using the colored beacons for oncoming traffic as a civilian. I know sometimes there isn’t time or there are other cautions, but the usual triangle signs are both effective and expected by most motorists……they see them and they know what it means. Same with traditional flares (if legal/safe) or LED “flare” devices now, either rotating or flashing. In addition to any potential glare/dazzling issues that can happen with a handheld powerful flashlight, there’s also the chance that drivers may be briefly confused and either not slow down or maneuver away, or possibly even drive into the confusing light source (really…that happens!). A handheld light waved manually is an ok backup but not a very safe option as a sole source of alert (and using them that way, wand covers/cones are safer than an open beam). And always be sure to place the triangles/”flares” way way back…at highway speed 100 yards is a blink of an eye so taking time to walk at least one of them back away 200 yards is smart.
imho, follow the examples of the professional road responders like police, EMT, tow truck drivers, etc. Stick to things that drivers know and expect.