Spodman, the scenario you give an example of is the situation at the present time. Why can’t each aircraft quote a GPS distance from a location (as they can do with DME) and then let ATC use a more enlightened form of separation, rather than 10 minutes?
In fact, I understand we were supposed to introduce some type of GPS distance standard. Remember we are a sovereign country. We can introduce standards that suit our present needs.
Before everyone starts shouting, remember I have always said “copy the best from around the world and keep the best of what we have here.” That is what I have always done.