Originally Posted by More Champagne Sir?
Unfortunately, you won't be able to through-check your bags at EDI. There is however a left luggage facility in each terminal at LHR, so you could get rid of your bags and jump on the HEX and spend a full day in London.
^^
Ten hours at Heathrow is enough to induce an early death, even with lounge access. There is only so much shopping a human being can handle in one day!