This is a possible real solution to the RAM speculation problem--and a few others as well. If leases expire, there is no need to liquidate unused addresses after three years since they'll no longer be tying up significant system resources.

I like the way that this proposal is modeled on the efficient way that computer engineers have already long employed to preserve the costlier resource RAM by swapping to disk when not in use. It seems obvious once you read it like this.

This idea deserves consideration.