On lines that have a London terminus, which stations have contactless validators easily accessible?
Because of how comparatively cheap contactless fares are, it can be advantageous when travelling into or out of London to use a combination of contactless and paper tickets... however that means needing to touch in and touch out.
For example, Riddlesdown has an on-platform validator easily accessible, meaning if you are close to the correct carriage it would be feasible to jump out, validate and jump back in... At Amersham, there are no validators on the platforms, but the ticket gates are very close to the middle of the London-bound platform, which would make it feasible to validate as well. Wimbledon, on the other hand, has validators only on tube platforms, which would make it infeasible to touch in/out from a train.
Is there a list of stations close to the contactless boundary that have validators easily accessible from the train platforms?