Of course it is. A list would be mostly useless unless it was editable. But, the content? That's another story, especially if the implementation breaks compatibility in a rather almost combative way.

Yes, you can obviously do that. But should you?

I certainly will leave edits to those who wish to use them, though, I still don't think this is a good move for the whole of NOSTR. Adding complexity to a pillar is the protocol is not what I consider a good thing. But, I'm also not a dev/coder so I can't really say much about it in a practical sense.

Rock on with your bad self.

Editing isn't so much the issue.

1. The method used in how this version of editing was implemented has forked nostr irreparably. This is without warning or consultation with other devs. This HIGHLY discourages a consistent protocol and will hamper further protocol development as it balkanizes. Nostr is too small yet to deal with that, and I am concerned this will be the end of innovation with emphasis on collaboration.

2. The issue is that there is more no cost to editing, and less with forking. The fact that up to this point what you type and hit send on a note is more or less permanent is a positive, IMO, behavioral modifier. When you know you can fix something, you will not put effort into anything. It's basically as trashy as fiat now.

3. Edits could always be done in replies, anyway. So now we have a broken ecosystem for something of very dubious value and also opened up a new attack vector. There are ways to mitigate this, but, I hesitate to propose anything since I'm not a coder.