Which clients have been specifically tested with the article format with updating that work as described above with npub.pro?
Not all relays (and maybe clients?) are required to honor all parts of a protocol just because a request is made. For example, a user can use a client to request a deletion of a post, but not all relays are required to honor this. Some clients do not offer the option.
Which ones did you find work properly?
It doesn't much matter which relays honor what - your signatures and timestamps matter. With old internet anyone could take a screenshot or save a webpage with old pricing (or even make a fake one) and start asking questions. On nostr you have signatures and structured events, so a) no fakes possible, b) much easier to prove you published newer event with newer pricing, especially if that event has comments and likes from other people.
Honestly, I'd say this is overthinking, edits/deletes exist, most relays support them, most apps support them, and bad actors will always find loopholes to ask stupid questions.
