Yep, and it's possible that running low on ipv4 address space exacerbated the situation, so many more small routes than there used to be, maybe not all getting

Yep, and it's possible that running low on ipv4 address space exacerbated the situation, so many more small routes than there used to be, maybe not all getting summarized during an outage they way they used to be, causing problems on peer bgp routers like you said.