This is starting to look good. Nothing really fancy, it's practically a guide on how to formalize and leverage a specific FIP-2 use case.
At the same time, the spec takes into consideration practical limitations and implementation hurdles (for example, how easy it is to implement at scale, with minimal resources).
Start a thread in discussions if you have questions, or suggestions, or any other feedback. Also, interested in applications that could leverage it, other than blog feeds.