Your post needs some serious NIP37.
But "no edit"???
I think that is the edit answer. Allows the edit with chain of changes, or delete replace, depending on how the relay wants to handle it. Backward-compatible, accommodate simple fixes, or in a system that wants to be a mini GitHub for every post they can, use nip 37 to do that on their client relays. This is how I understand it as put forward. Just a matter of getting the clients to onboard it. See my other mock ups for Primal to adopt.