Since you are trusting a third party to validate/invalidate token ownership anyway, why not let them run a centralised infrastructure for bids/escrow as well. B

Since you are trusting a third party to validate/invalidate token ownership anyway, why not let them run a centralised infrastructure for bids/escrow as well. Bids could be published (via a Git repo for validation, or via a Transparency log) to maintain integrity. The security model doesn’t change - this party could sign away your land ownership already. You don’t need to trust an arbitrary blockchain, or mining economics or get all land owners to buy multisig hardware wallets.