All backends must be updated.
All frontends must be updated.
This will be more complex, you will have clients that suddenly supports way more following list than standard kind 3, what then? You have massive fragments between the apps that the user uses.
How does one choose which of the thousands of following to keep in sync with the legacy kind 3?
There are so many potential scenarios that is problematic already today, this introduced its own set of scenarios that must be handled and mitigated, not just by frontends, but also backends.
My notification service will now need to listen to both kind 3 events, and to multiple 33000, and have some advanced logic other than: "send notification to the last pubkey added to the list".
I get the wish for this, but I'd rather not extend existing patterns with even more complexity, if it doesn't really bring a whole lot of benefits that makes it a no-brainer.
