New experimental feature: "Let me use Oyster/contactless to travel cross-London"
There's now a new toggle switch which can be enabled in the
More Options dialog to specifically request that
cross-London fares are excluded, and that the journey planner splits journeys into two ticketed parts (one to enter London, one to leave London - with the bit in the middle left unticketed to be paid for by the customer separately using Oyster, Contactless or Apple/Google Pay). This will initially only be available on the RailUK Forums branded site whilst the functionality is considered experimental.
The benefit from this approach is that whilst TfL continue not to support modern barcode-based National Rail ticketing standards, you are
much more likely to be able to have your booking fulfilled as E-Tickets with this setting enabled, as there is no need to issue tickets valid on e.g. LUL services where only magstripe tickets can be accepted at the gateline.
I would recommend railcard-holders make use of a Oyster card with auto-topup enabled instead of contactless, as the latter mechanism continues not to support railcard discounts being associated with the passenger's payment method.
Feedback welcome.