@HoltWilts The master socket is isolated from the 2 line wires via the Internal electronics inside the Master Socket, The 5c version of the socket has real good isolation, hence asking to have you send picture up to see, the extensions on that 5c socket are all changed when OR come to fit and wire it up for the FTTC connection, so if THEY did the job right, and you had a fully working line, extensions et al, and then went FTTP or NOT it does not matter. OR have a NEW socket that they can fit, but trying to get one is like trying to find gold in the Sahara Desert... If you wanted to be fully safe and this can only be done when on a FF (Full Fibre only) line as the copper is now completely done, then the AB line that goes away to OR, those tails can be lifted of the master socket and for sure it is going nowhere at that point ever.....
And finally you just attach the wire from the picture, and all your extensions become powered of the EE Router, only possible issue is ringing and if voice is good enough you have got to drive the signal around the house cable, and new phones are a lot less power hungry than a phone 30 years old if you find it's struggling, unplug an extension. Its all about the REN...👍
