First of all, I would say I don’t have a vested interest in this as it’s not a service I use, nor am likely to. However I work with people who do, so have some idea of feelings from a user perspective.
And those feelings are that 12-car working was promised, and notwithstanding Covid this is the service people expect to be delivered. People really aren’t interested in having a babysitter sitting in a cab or walking up and down the train, especially on peak services where personal security isn’t a salient issue. I do agree that the immediate priority should be delivering a robust 8-car service though.
I’m not really advocating DOO, as IMO the optimal method of working is with a guard. However if this is causing issues then absolutely DOO should be looked at, either fitting bodyside cameras or CD/RA, which shouldn’t be a massive difficulty given the relatively small number of stations served.
In the longer term, again if this is such a major issue, perhaps it might just be easier to find a way of getting gangwayed stock onto the route (something involving 387s perhaps). There is absolutely no need for gangways on this route, but we are where we are. Without getting too speculative, one does wonder whether there’s even a case to split it off from EMR and have it run by TSGN, albeit not part of the Thameslink network.