(Apologies if this is flogging a dead horse, but some messages are worth repeating, if for no other reason than to illustrate the down side of not understanding the proper rationale for CIDR.)
I thought the dead horse was the conclusion that small ISPs should use whatever means the ARIN rules allow in order to get PI space. Having used provider-assigned space for a couple years, I can firmly say it sucks. Even if I had to talk to every tier-1 to get my de-aggregates accepted, it would be MUCH less hastle than having PA IP space. And your suggestion has technical deficiencies as well. I have a leased line between Toronto and Ottawa, so I want to announce my Ottawa IPs to my Toronto transit provider as well as an Ottawa transit provider. And the reverse for the Toronto IPs. My understand is trying to punch holes in PA space is much more difficult than de-aggregating ARIN PI space. -Ralph