yeah I read that thread, I suppose its like the problem that existed last year. They will keep publicly denying the problem with the BT group's policy that its better PR to appear incompetent and not acknowledge issues instead of telling people they working on it. But in private they will acknowledge the problem, and one day the problem will be resolved as if by magic whilst the denial will continue and they will pretend the fix is coincidental.
This is what happened when they moved to the dedicated WBC platform, they pretended it was nothing to do with the shared WBC overload, and it was pure coincidence the move happened at that time.
Sadly it does look like BT group seem to follow VM's guidelines on network capacity management in that they will provide enough capacity for what they consider to "just be enough" known as running things hot, then in situations where they misjudged capacity requirements this sort of thing happens. Whilst sky build their network so that peak utilisation is under 50%. Meaning if there is unexpected growth in demand or spikes for things like ios updates the network can handle it. Two different approach's.
Plusnet will remove the bottleneck I am sure, but since they wont acknowledge the problem it means they wont report when it will happen and you just have to wait for it or change isp.