NIP-03: OpenTimestamps Attestations for Events
Discussion
"While OpenTimestamps can create timestamps without a local Bitcoin node, to verify timestamps you need a local Bitcoin Core node (a pruned node is fine)."
OpenTimestamps looks like overkill.
What do you think of 'declaration of successor' events to be blocked by relays when they are older than lets say 7 days?
Relays shouldn't have to be trusted.
It's not really true that you need a full node to verify OTS timestamps, you can use an SPV-like trust model where you just have the Bitcoin block headers and check their POW. The headers are just 80 bytes per block.