Another note is that I see bitcoin.pdf being mentioned but I couldn’t find word “mempool” mentioned Hornet-wise yet.
Indeed, so far Hornet is focused on the consensus aspects of the protocol: creating a pure, declarative, executable specification of consensus rules; and demonstrating a novel engineering design for fast and memory-efficient validation and sync.
Hornet has a layered design where consensus is separated from mempool and policy.
Thanks for your interest, T#