Right, that’s interesting.
Firstly, Kerry: National Rail smartcards which contain a travelcard allow travel within the zones without a separate Oyster card. I didn’t realise that they also provided journey history, which is good to know. The GTR version of the Key also allows PAYG travel on GTR services AFAIK, though I’m not sure how that is worked. If they rely on a data feed from TfL there might be issues.
Y’ossi: Given that you have a travelcard covering all of zones 1-6 I think touching pink readers is a little superfluous. If you truly were ending a journey at a station with one you’d need to exit via a gate. The issue we usually get is where a person has a ticket from say Brighton to Clapham Junction and wants to go onwards using Oyster PAYG without leaving the station. I have never seen a pink reader display Exit so I’m slightly skeptical that one would. Usually they display valid for interchange if using Oyster and touched in, or Enter if not touched in. With contactless they just say card accepted. I will follow this up though, so thank you for bringing it to my attention.