.. I also hope that all the routes intended for 10-car operation will be fully 377/6 by next May, including on Saturdays.
How could they possibly be 'fully 377/6'?
There are 26 units, and 24 daily diagrams. So that allows 12 services to be operated as 10 car trains. They are planned to be used on the following routes, as previously discussed:
Victoria to Dorking/Horsham via Hackbridge and Epsom
Victoria to Epsom Downs via Norbury
Victoria to West Croydon via Streatham Hill
Victoria to London Bridge via Streatham Hill and Crystal Palace
London Bridge to Epsom/Guildford via Norwood Junction
London Bridge and Victoria to Caterham and Tattenham Corner (train divides Purley).
So 12 trains spread over all those routes, in two directions, so less than 1 train each way per hour per route. Other methods of providing 10 car trains must continue at the same time, even when all 377/6 units are delivered...