R610 has long been an anachronism. The MoD has never released figures showing how often it's used but these days I bet the answer is "hardly ever". The days when there were hundreds of strike aircraft poised to fly low level night IMC to drop nukes on Eastern Europe are long gone, so the rationale for that airspace doesn't exist.
The MoD is supposedly signed up to the concept of Flexible Use of Airspace but the reality is they cling on doggedly to every piece of sterilised airspace they have.