I knew a bunch of folks from 18F and the USWDS team. You could not find a more capable team of designers, developers and true user experience professionals. They cared about the users and they cared about good design.
Not to dismiss the X-files team, but 16:9 was already around when they started. Just not in the states. Japan started getting 16:9 CRTs in the early 90s, Europe followed in the mid 90s. America lagged another half decade and effectively skipped 16:9 CRTs mostly going straight to plasma/lcd.
You can. The Vision Pro supports a primary user that retains settings/user account/AppleID and a secondary user with gets a “guest” account that resets.