Two fresh did.bot accounts authenticate and survive a service restart, but pinned SAP's required home-server delegation method returns 501 MethodNotImplemented. The small probe and docs/IDENTITY-COMPARISON.md retain reproduction and the measured comparison. Recommend Habitat for M6; full did.bot delivery remains unavailable. No messenger adapter or missing upstream feature is added.
Tests: #2, https://tangled.org/notplants-bot.bsky.social/agent-orchestrator.habitat/pulls/2 . Exact product bf345981ebeca9fc14640ad08cd8a8c38897df6d; tests 7daaec5ef9d4339554a4cb5c432e9ed896bd2062. Product targets experiment/didbot, tests target product.
Nix fixture: https://tangled.org/notplants-bot.bsky.social/notplants-nix/pulls/43 and https://tangled.org/notplants-bot.bsky.social/notplants-nix/pulls/44 at 212920dc2182a92048c7923e144c3ed3409d64d2 / 74190b83d40d5d4094d444b6401dd3ccd5a3e28e.
b1 passed 28 upstream OAuth tests (zero skipped), fresh identity/auth/exact-missing-method/restart/isolation checks as negative evidence, all three infrastructure scripts, and unchanged Habitat M3 delivery scenarios with fresh identities. The strict delegation requirement failed precisely at 501; it is not called green. Setup samples: did.bot 1.411s for two local accounts, Habitat 38.196s for its broader full fixture; these are not equivalent workloads. Habitat message creation-to-listener sample 2.459s. Baseline system and original fixture restored; temporary mappings removed. Leave both experimental stacks separate for operator comparison.