Thanks for posting this.
Based on your success I installed it on my 4th gen TC in anticipation of the public release of macOS 27 (I’m still on Sequoia) and hope to use SMB thereafter to continue the encrypted secondary backups that I make to the drive with CCC.
It’s an impressive hack, with an unexpectedly sophisticated GUI installer and maintenance app. Kind of remarkable, really. I don’t use Time Machine, but I've had good success running CCC backups over SMB so far, albeit at speeds noticeably below those that I achieved with AFP. If nothing else, it’s good to know I won’t lose access to the TC disk past Tahoe.
Interestingly, I didn't deploy the "boot hook" firmware flash that's said to be required for automatic Samba restarts when older NetBSD 4-based TCs are rebooted, yet in my tests it's always restarted itself anyway.