[44net] directly routed subnets

I've gotten several requests for directly routed subnets (ie, BGP announced CIDR blocks as subnets of 44/8, not tunneled) for ham radio use. These are people who want to set up HSMM networks in the ham bands, D-Star constellations, etc. I thought I'd ask folks what they think of the idea of setting aside part of the address space for that purpose? What issues do you see arising from doing so? - Brian