@weaver, I noticed two issues.
In the customizer, when viewing a single post page with featured image positioned above title, selecting alignwide for the featured image single page is not reflected in the customizer view (it is in the live site). alignfull does refresh properly in the customizer.
In the Legacy admin > post specifics > featured image, the align options are missing the new alignwide and alignfull options.
These are only available in the customizer.