Errors on the line can be there even when no data is being transmitted so it is irrelevant if you use it or not.
There is nothing you can do.
Openreach are aware that some lines do get stuck on sub-optimal profiles, despite line improvements (that court case that BT lost led to changes to the way DLM moves profiles up/down). They are implementing a number of changes to address this, some of which should go live next month.
It does look like ISPs will 'soon' be able to force DLM to reset, but I cannot give you a date. Changes to the DLM algo next month should hopefully make things better for you if you're line is performing well.
Not my info.