Oh so relays are going to need to be modified to not check for a signature then? How will a relay know that a given event is meant to be unsigned? I think having a dedicated kind would simplify this.
Exactly right! nostr:npub1gcxzte5zlkncx26j68ez60fzkvtkm9e0vrwdcvsjakxf9mu9qewqlfnj5z nostr:npub1l5sga6xg72phsz5422ykujprejwud075ggrr3z2hwyrfgr7eylqstegx9z, this is why I was waffling on using Kind: 1 or not. Since everything inside is unsigned (and encrypted until it's decrypted by group participants) it does function very much like a private feed of it's own.
Discussion
Nope these unsigned events are contained in other events and encrypted with MLS magic. The event that is published to relays is signed by an ephemeral key.