Rather than signing dates, they should sign a hash of the block header that was mined 10 minutes ago.
That's indeed smarter than a date, but note that I asked to provide the topic ID too.
Yes, it would prove more eg. that the signature was created recently.
But if we use a Bitcoin address as the signature message, so we can build a 'signature chain' where the next owner can sign it and transfer it to the next owner.
Created a 'signature chain' transfer in the thread
old Bitcoin addresses as 'NFT' on the Bitcoin blockchain - a signature chainhttps://bitcointalk.org/index.php?topic=5425241.msg61393177#msg61393177