I am please to say that BT has recognized this problem and are doing something about it. In the Openreach GEA-FTTC Fact Sheet they have the following advice to ISPs when implementing FTTC
Dynamic Line Management (DLM) features
Match the way a line is managed to the way
your customer uses it:
Standard – best overall balance between
speed and stability for general internet
Stable – prioritise stability over speed for
videoconferencing, home workers and
businesses transferring data and IPTV
Speed – prioritise speed over stability for
In my own case I have managed to get my profile set to a value that is just short of three times what it was previously. The other factor is that with no other changes my line is now more stable than it was before !
Note that this only resulted from manual intervention by a forum moderator.