On Nov 23, 2021, at 11:12 PM, William Herrin <bill@herrin.us> wrote:

1. IAB or IESG requests the IANA team to delegate one of
the 240/4 /8s to the RIRs on demand for experimental
purposes for a fixed period of time (a year or two?).

I like research but what would the RIRs study? The percentage of the
2021 Internet reachable from a station assigned a 240/4 IP address?
Suppose it's 95%? Or 50%? Is there a difference? Neither one is enough
to deploy the addresses for 2021 global use.

Lots of people said similar things when 1.0.0.0/8 was allocated to APNIC and they said similar things when 1.1.1.0/24 was stood up as an experiment by Cloudflare and APNIC, yet 1.1.1.1 seems to be pretty popular.

5. Armed with hard data on the usability of the 240/4 /8s
allocated, people can scream past each other much more
authoritatively on the topic of what to do with 240/4.

Which is not particularly valuable. We already know the addresses are
dysfunctional on the 2021 Internet. There's no credible disagreement
on that point.

Seems to me that a number of folks on this list and during this discussion would disagree with a blanket assertion that 240/4 is “dysfunctional on the 2021 Internet” - some of them even wrote a draft discussing the possibility.

2. IAB or IESG requests the IANA team to delegate one of
the 240/4 /8s to the RIRs on demand for experimental
purposes for a fixed period of time

But that still starts with:

1. Move 240/4 from "reserved" to "unallocated unicast"

OK, but this seems like a quibble. The status for 240/4 is “ RESERVED: designated by the IETF for specific non-global-unicast purposes as noted.” The “as noted” part is “Future Use”. As far as I’m aware, “future use” would not preclude “experimental use” however if it makes people feel better to have an IANA considerations section that says the prefixes need to be moved to ALLOCATED, I struggle to see how that would be a problem.