On 19 Nov, 17:55, MIG wrote:
*It ought to be possible to
get the appropriate fare without doing ridiculous things like getting
off during the journey,

I occasionally have to travel from Fulwel to Barons Court during the
morming peak.
I have found the cheapest way is to buy a single from Fulwel to
Gunnersbury and make sure I am by the right door when I arrive there,
so I can hop off, touch my Oyster in on the platform validator, and
hop back on the same train again to go onwards to Barons Court. I've
never been left behind yet (although I do end up standing the rest of
the way).

Jon