I laughed at "double secret probation", thanks for that! And thanks for the additional data points so far.

I'll continue to research things on sport pilot and check more directly with AOPA (and with my doctor!), while keeping more limited ultralight flight in mind as a backup. My primary concern is with safety, and my secondary concern is with being in compliance with law and regulation.

I'm not satisfied with "they won't notice unless you have an accident"; I want "they won't care even if someone e-mails the FAA enforcement department with details of your medical condition and what medications you take, because they'd agree you're safe to fly under sport pilot rules", and I'm not yet convinced which is which.