Well, your question is interesting to me and I feel compelled to answer it, not because you need to hear what I have to say, but because I need to work it out into words.  So here goes.
I USED to overengage. To the point of pain.  To the point of mentally rehearsing converations and wording letters to people ALL NIGHT LONG.  The the pain and frustration of the whole business got to me.  I ran headlong into the truth of your tweet some years ago.  I would like to say that I learned to choose to disengage, as you have, but instead, I turned the whole response factor OFF.  Now nothing much excites, or riles, or ignites me.  Not at least in person.  However my writing still catches the waves as they come and rides them for a season.  I am intrigued by your suggestion that one might respond for a season and then, when you sniff out impending futility, turning back and walking away.  I don't like the thought of myself as a deadpan person.  I am way too passionate for that.  I know I've had arguments (or debates) where I realized that NO ONE was going to win, and I walked away....but I guess in my all or nothing personality, that distance and lack of vulnerability was too enticing.  It was a fortress...a wall behind which no one could reach and sway me.  So I bought the whole kingdom behind the wall.  And stayed there.  I'm still not sure I have the ability to quell my passions and learn to shut them off at will, but it does seem to be worth a try.  Question is: can I turn them back ON??