Kind 3 relays is a very old hack, never were standard, and need to be sunsetted. My intent is that the pain of coracle's incompatibility will accelerate the migration to nip 65. I could be wrong, and maybe it should be added to the spec, but until it is I'm playing dumb on purpose.
Discussion
It's one thing to not read kind3 relays but to write kind3 destructively ... is evil. https://github.com/Giszmo/nips/blob/protectTheUnknown/24.md
Sadly that nip was rejected but mainly because it's not an implementation possibility but merely a reminder.
I do agree with this nip, but don't currently do it in Coracle. Something to improve. The difference between not writing kind 3 relays and nuking them is a valuable distinction.
We already publish those, at least on test flight