First of all for the past 20 years or so, cars have had the third brake light, not to mention brake lights are brighter than tail lights. So that ole practice really doesn’t do much to a tail gater except irritate them more. Its like two people insulting each other to the point where it comes to blows. Who started it doesn’t matter, they are both as guilty for allowing the conflict to escalate, no?
I usually just maintain my speed and try to turn off, change lanes, or otherwise get them off my tail as soon as I can. Plus I keep a more watchful eye up ahead to avoid any quick moves. Had one yesterday going 60 in a 55 on a two lane coming back from the lumber yard. Heavily patrolled so no way I’m going faster. OTOH, you never know why they are in a hurry. Maybe just idiots, but maybe needing to get some place fast, like the hospital. Who knows?