"Mizter T" wrote:

I believe the trains actually reverse out-of-service at South Croydon, but
southbound they tip-out at East Croydon - not sure how good they are at
doing this there.

I recall one of the South London RUS recommendations regarding the
MKC-Watford-Croydon services was that of reversing at South Croydon (not
considered ideal for whatever reason but doable nonetheless), but perhaps
I simply and erroneously read into that that they'd run in service to/from
South Croydon.

http://217.23.229.206/jpclient.exe (Traveline North East & Cumbria) [1]
suggests that the trains use platform 5 at East Croydon in both directions,
arriving generally at xx57 and departing at xx10, so I assume they lay over
there and don't need to go to South Croydon. If I had the time, I would
check Traveline to see if any other trains are booked through platform 5 at
that time, but I currently lack the motivation to do so!

I do, however, believe you are right that there was at one time a suggestion
that these trains might run to South Croydon in service.

[1] It's bizarre that one has to use this particular resource, but other
regional Travelines don't show the platforming!