So all clients need to know about all kinds even if they don't deal in them, and render their own alt string, and only fallback to something generic like "unknown event kind=230987" if the kind number wasn't coded at all (new kind, or not documented kind). ? I like that. Less data.
Discussion
Yes, but the point is that "knowing" is cheap, doesn't require any code and can be just slurped from someone else's registry.
Turns out maintaining such a registry is not a task easy enough that can be done in 15 minutes.
I got it started here: https://github.com/fiatjaf/alts
If someone else is better at dealing with AIs than I am maybe you can try making it more useful because aside from the kinds I manually edited most are very useless (well, actually they're not entirely useless, since they have the event kind "name", which is something).
I think we should probably remove the {{pubkey}} and {{created_at}} from the templates, as clients can just always show these anyway, an in a nicer manner than a vague text, since they're present in all events.
Not really. All they need to do is to open an njump.me (or similar) preview for the unknown kinds or just implement nip89 and send to other clients. Either way, Alts are not a good solution.