As I state elsewhere on this thread, Oyster PAYG is valid for use on
the WLL these dfays - and that includes from Clapham Junction.

Yes I know, but on this occasion it will be better value to get a
through ticket or a travelcard. At the weekend, when the Network Card
cap doesn't apply, it may very well be best to buy a return to CJn and
then use Oyster.

Although one problem with Oyster is that it doesn't allow for change
of mode on one fare. So a journey involving two buses, or a bus and
tube, or maybe here - if it's raining I might want to get the Tube to
Shepherds Bush and then WLL - you get charged twice, more than if you
took a journey of equivalent length on the Tube, even changing lines.

Many European transport systems allow you to change mode on a single
ticket, within a certain amount of time - and I think Oyster should be
programmed to do this.