Vectoring when multiple cabinets are present is more difficult, only way it can work if all the same DSLAM and a dedicated fibre link between them JUST for the vectoring data so they can share information when doing the calculations.
Neil McRae, in his talk on G.Fast at uknof, suggested that manufacturers aren't working on a link between cabs, for vectoring, with any real seriousness. He went on to suggest that once an operator has deployed a fibre cab, then they effectively own that location forever more.
This was in answer to a guy from Warwicknet, so he hoped they intended to deploy G.fast at their sites...