That is definitely a problem indeed, but it is a problem because you are using Nostr with key delegation and Nostr is very unfriendly to that.
If you take a step back and think from the point of view of the normal web, you don't need this mess.
For example in Bluesky, you can rotate keys and recover them and delegate keys to a server etc.. but you don't need timestamps, because there is a source of truth that you can rely on.
A master key that in a protocol with strong consistency and single source of truth can easily declare the entire state of blessed events, and delete everything else that they don't like.
Think of a website, once you change your server and point your domain to a new server you are done.
But yes in this paradigm of Nostr signed events thrown everywhere you need OTS for all events, but I am afraid you are going to be disappointed because Nostr is unfriendly to all forms of delegation, so after you try to conform to its limitations you will find that no one wants to use this system, we have historical examples of key delegation schemes that was removed even after wide adoption.
But I can't blame you for trying.
