I will have to check but it is possible that the spacing is not enough. Apparently it should be 2.4-3.6m (8-12ft)
That depends entirely on the form of the tree - obviously any leaning towards tip-bearing means you are likely to choose a wide shape to prune towards.
However there are still quite a lot of spurs and if you prune to keep the ones closest to the tree it will produce more each year and you can end up with a productive cordon - and yeah, this might very well be another reason why mine took so long to produce a decent yield.
But it certainly helps to remove the heart-rending task of fruit thinning!
Cheers.
