"Tim Roll-Pickering" wrote in message
...

What happens now if one touches on the platform pads when interchanging?
Does it terminate the PAYG journey completely or does touching out further
down the line make it an unnecessary interchange touch?

Apparently the system sets a sort of 'partial exit' if you are already
touched in; another poster here, 'Mizter T', coined the term 'soft exit'.
If you aren't already touched in it starts a new journey.

Whatever it is called behind the scenes, the journey can continue. I think
it gets sorted out either at a subsequent proper exit through a gateline, or
after some sort of timeout, whichever comes first.

Paul S