Simon Hewison wrote:

One daft thing that you can't do (but I'm sure you used to be able to

do) was use the credit on an oyster card at a tube ticket machine to
buy
a paper one day travelcard.

You have never actually been able to do that. The large touch screen
machines at some stations (Tottenham court road and others) used to
have a pay by oyster option but there was a sign saying not to use it