> Gov't is mandated to use AWS Gov instances which are quite easy to distinguish
That's not, in fact, true. The certifications that apply to AWS Gov make it easier to meet certain government compliance rules that apply to certain categories of data, but it is possible to meet the standards on a platform that isn't certified or certified to a lower level (but it means more administrative work for the org using the platform) and many Commercial AWS offerings have FedRAMP certifications, anyhow. I work in an org touched by FedRAMP, and which is almost entirely on AWS commercial, not Gov.
That's not, in fact, true. The certifications that apply to AWS Gov make it easier to meet certain government compliance rules that apply to certain categories of data, but it is possible to meet the standards on a platform that isn't certified or certified to a lower level (but it means more administrative work for the org using the platform) and many Commercial AWS offerings have FedRAMP certifications, anyhow. I work in an org touched by FedRAMP, and which is almost entirely on AWS commercial, not Gov.