I really don't get what the OP is arguing about here... he'd rather that we introduced this expensive new technology to test whether signalling could be transformed into something much more modern with... the operationally independent "one engine in steam" line from Preston to Ormskirk? What benefit would that be (other than for people who grew up near Ormskirk, presumably) - you might as well introduce ETCS on the Stourbridge line!
I'm guessing that the problem here is more about ATW/TfW not having enough 158s spare to provide the capacity at the busiest times of year to suit the OP (and another dig about how the new TOC hasn't ordered as many trains as the OP would have ideally wanted to have)? But that's really a TOC issue - there was no reason why the new technology couldn't have been put on more trains other than expense.
But when the thread veers off into talk of InterCity services with buffets to Aberystwyth and the like, I realise that there's not much point in trying to have a balanced argument about the best location for new technology (that requires something reasonably complicated/ long/ sufficient PVR to get some kind of critical mass etc) and is just about How Much Nicer It'd Be If We Had "Proper" Trains And Everything Was Like When I Was A Lad...