My understanding is that it's all or nothing. All the connections to the cab must vectored, and it'll work, or it won't. (and could worsen some connections).
To do this the cab must be able to support vectoring, and all of the subscribers must have a vectoring-capable modem/router, and have it enabled.
So, with a lot of old BTOR modems out there, it becomes quite a big and expensive project, especially when they're in the middle of the actual rollout of FTTC.
I suspect (not in the same was as Ribble!) that they are installing capable DSLAMS, and a consumer replacement project will be a way down the line.
ZeN Office
Fritz!Box 3390