I spoke to EDF this afternoon (06 Dec 18) and was given current pricing for E10 from the Complex Metering Team which was better than my current supplier (SWALEC/SSE). Approx saving = £250 pa. They confirmed off peak 10 hours and said it is not E7 on an E10 meter.
Thank you for this hugely informative site. I cannot believe I have never come across it before having searched E10 numerous times in trying to sort out my many issues over the last 15 years!