I have done several back to backs at DME this year, and most recently 2 weeks ago.

I can confirm it is an excellent location to do them, as long as a valid Russian visa is held, you have the return boarding pass before arriving at DME, and you are HBO.

Simply proceed to the international transfer security checkpoint, show your return boarding pass and you exit into the departures area of the airport.

Aircraft layovers at DME are at least 1hr 20mins, so there is plenty of time to visit the lounge.

Usually I am asked why I am returning straight back to LHR, but I simply explain I am doing it for miles and points.

But it is pointless attempting it without a Russian visa as BA will not let you board at LHR.