I did go to Abington this afternoon and got charged on both Gridserve and Applegreen successfully. Gridserve was absolutely no problem. Applegreen was being annoying about reading people's bank cards (not just me) but when it finally did deign to accept my card it charged the car just fine. That's actually a first for me, on an Applegreen charger.
Very reassuring.
I was aware of the heavy cable thing but it didn't seem to be an issue for me. But on the other hand an orange Trophy in the next bay to me didn't connect to the charger at first, but when I unplugged the connector and plugged it in again for them, it connected. Maybe it's the angle when you handle the connector?