I think the 125 Group needs to correct it's XC HST 2018 diagram sheet for from 8th October - a passenger told XC that on Saturday one of the services was half the coaches it should be. This was the 12:45 from York to Sheffield (09:00 Glasgow to Penzance service) which XC say it was correctly formed (4 or 5-coach Voyager)!
In fact the XC HST Saturday diagrams on the 125 Group website were the summer Saturday ones.
Common sense though to use an HST on that Glasgow to Penzance service which would be an ideal service for passengers to get this train back from their holiday in Scotland / North East in the morning back towards Birmingham, Bristol and the South West. They'd arrive home for tea!
0900 from Glasgow has been HST operated at times , latterly on some Saturdays .