Mentioned in the West Midlands ITT is this suggestion:

https://www.gov.uk/government/upload...55/wmf-itt.pdf

"A description of how the Franchisee will utilise smart ticketing
technologies to provide customers with a flexible and convenient
solution when travelling into and around London from stations
between London Euston and Northampton and Watford Junction
and St Albans Abbey, and also for customers making
intermediate journeys on these routes. Bidders may consider,
for example, TfL ticketing technologies (e.g. Oyster/Contactless)
or a Franchisee ticketing technology that integrates with the TfL
ticketing area."