DD9QP:
Keep in mind that in Europe there is a "European HAMNET" driven by 16 countries. It was founded in early 2000s and is using 16bit-ASNs because the 32bit-range was not available at that time. There is a registry to avoid ASN-doubles and it is working very well.
Well... We have been using that but the exact reason for this whole proposal was that I was extremely p*ssed off this week when I discovered that this registry only wants to allocate 1 contiguous range of AS numbers per country, and allocates only tiny ranges. Every time one outgrows the range of numbers, one is supposed to renumber the entire network. What a joke!
Initially we (the Netherlands) got an allocation of 4 AS numbers, and when we needed more, the range immediately after that turned out to be already allocated since before we got our 4. So we apparently had been put in a hole left by someone else moving.
When I noted that I did not like this and would like a second block to expand our allocation, the owner of the adjacent block was requested to renumber!!! He even complained that he had to renumber twice before. Then, we could expand our allocation to 19. And this process was completed before I even could note that I did not want to make others do the work that I did not see as useful.
So then the decision was made to leave that registry and find another solution where neither we or others were forced to renumber or live with sub-optimal solutions (trying to limit the number of ASN).
Our block can be returned to the free pool or be given back to the previous owner in case he did not start the actual renumbering work.
Rob