I asked them about this, far too early for a reply, of course, as I sent it way too late.
By the way, I see Openreach is advertising their Broadband Boost service. Line #3 ( cwcc@a.3 BBEU20700055 ) had a fault a couple of weeks back at the same time as the new line was being installed. It has always, since the very beginning of time, been slightly under par. The line 3 downstream sync rate is about 200k lower than the other pair in the same drop cable. Line 3 is at 2737kbps downstream sync, as opposed to line 4 BBEU20709519 (the other pair in that drop cable) which is at 2924kbps.
Whilst line #1 (BBEU20700042) enjoys a downstream sync rate of 3037kbps - so, what, around 10% worse downstream? Also the line #3 upstream is not great compared to line #1, only 85% of line 1’s upstream sync iirc at 440k as opposed to 515k.
I wonder if Openreach could improve it by 10% by inspecting and tweaking some joints?
I wonder