Oddly enough, the West Country being a tourist detention, I have been travelling into, out of and around Cornwall on trains on and off for 40 years or so, at various times of the year.
How often do you travel on the Cotswold Line? Rarely, if ever, judging by the things you say above and obvious blanket refusal, just like irish_rail, to accept anything I, or others, have said about the way that five-car and nine-car sets are being used on the Cotswold Line - ie, just the same way HSTs and 180s/Turbos were used on the various services, at various times of the day, until last year when IETs were introduced on the route.
PS: Clearly I have been hearing things and hallucinating when on board a number of morning peak trains recently and catering announcements offering hot bacon rolls have been made and trolleys or staff members have been sighted transporting such things along trains in insulated bags. Clearly there are issues over the consistency of the catering offer and room for improvement but HST buffets weren't exactly replete with exciting food options in recent years either.