After passing a couple riders and spinning up for a short overpass climb, ching, chain dropped off.
So it was several metres of shamed walk as the riders went by and I could roll off the other side of the overpass, and stop in the shade of a tree to loosen axle and put chain back on.
It came off again a kilometre later, so I aligned the wheel away from chain and made the rest of commute in, taking it easy on pedalling in shifts and bumps of the chain.
So tonight the tugs will go on. It also happened to the Felt MP after a curb dropoff, so is now more inconvenient and time wasting than punctures for the year.