No extra paths needed on the east coast as it’s an existing service that’s extended to Cardiff.I'm not sure about splitting them at Gloucester, this will add journey time to services to and from Plymouth. And the logistics of reversing at Gloucester could cause further delays in getting back on to the GWML in the Bristol area. Perhaps a better option would have been to run them as single sets and via the West Coast Mainline. The East Coast already struggles with bottlenecks at Doncaster & Leeds and that's without the Reading-Newcastle services back to a full service pattern. On a side note, this does seem to indicate that the remaining 221s from Avanti are planned for CrossCountry. I doubt they'd be able to run such a service at the moment - especially having just lost 5 HSTs.
That would be 221109.![]()
Splitting at Gloucester already happens on the southbound service (I admit I don’t know if this is daily).
It’s certainly happened on the rare occasions I catch this service when I’ve had to be careful about which portion is continuing to Bristol and which is going back to Birmingham. it should be fine for timings going down to Plymouth.