[moderation seems slow; resending from subscribed address instead]
I suspect I've sufficiently chummed the waters, I'll kick back and absorb
all the reasons this is a whack idea
Short summary: it's not entirely whack, but no one has yet put forward a working data model. The scheme in Bill Manning's INET'98 paper might have worked for classFUL addresses, but not CIDR. I think there may have been similar problems with Lutz Donnerhacke and Wouter Wijngaards' scheme(s) from 2008.
Joe Abley's problem statement on this list gets to one of the issues. Your answer to him of "New prefix-based RRs? And perhaps even a new .arpa or in-addr.arpa subdomain" is a bit short on details. I challenge you to work out the details. Once we have something concrete, then we can pick apart why it won't work, tweak, and repeat.