He also proposes supporting regular onion packets for now and broadcasting extensions for future use. Christian Decker raises concerns about providing a precompiled header with HMACs for the final recipient without knowing them upfront. They discuss the possibility of implementing seamless rendezvous routing and conclude that dropping per-hop HMACs may be necessary. They also agree that key rotation alone is simpler than a timestamped log of secrets and should suffice. The group also discusses using Schnorr keys within the Bitcoin network for space savings.