When suggesting that Debian provide a security-supported release stream other than stable, the usual response is that the security team doesn’t have the capacity to support another one. That why I pointed out unprompted that I’d cut stable if there isn’t capacity for multiple security-supported channels. I realize it would be a big change for Debian.
Also: unstable can’t be the channel for casual users with rebranding, since there needs to be some smoke testing channel before the one for casual users.