I managed to get it SMPF about two years ago now. I told them when ordering it over the phone that I was in contract with BT and my line and rental must remain with them.
I guess I could try it again, but MPF isn't an option unless Sky can tell me they'll be live when my cabinet goes live for FTTC or I can exit my contract if they aren't.
ZeN > plusnet > entanet > <aaisp.net> > Sky LLU & IoW Cable.