Hey kitz, here's an email I received from Origin's 'technical' team when I asked if my profile could be changed. What's also quite re-assuring is that before providing this we exchanged multiple emails as they needed to complete some checks and all responses were in SLA. In mine and my brother's case, this is based on using Vodafone's LLU:-
"Hi X,
Checking this for you, we should be able to change the IP profiling for the line, including the DLM profile. Please bear in mind though that if the profile is changed and there are then instabilities, the profile would need to be changed, or the line will experience multiple drops.
If you have any further questions please don't hesitate to contact us via email or on 01302 235060".