The only correlation I have found in my journey, and it's still kind of hunchy, is that breath ketones measured by Ketonix meter seem to have about 24-48 hr lag related to both carb intake and exercise and even fasting - It's like my body is a "ketone sink" as in "heat sink" kind of thing.

Don't be alarmed if they continue to drop, just wait it out at your 20 carb intake, they may return or they may not drop at all if it was just the one instance of indulgence - don't know.

Also, as Mama Sebo pointed out, good on you for sharing. Thanks Bill!