quickymart:
Nope, not going to happen.
It would be a bit like asking Sky to use your own decoder, etc - which wouldn't happen either.
I did look into building my own decoder once - there was hardware you could use but you did need a Sky card. It was a long time ago and a bit of a pipe dream.
But this is a slightly flawed analogy because decoders only receive. Installing your own ONT means it has to work in both directions and therefore be acceptable to the other end. As they will have visibility of it (unlike a decoder) they can turn it (the fibre connection) off at any time if they don't like what it is doing.

