In reply to Brian Gardner.

One beta-level issue: try using a touchscreen to close the navigation on any of those sites. It's currently not possible without either reloading the page or selecting a menu item. This bug has been present in Gutenberg since at least May 2021 when it was first reported (it's since been fixed, reintroduced, and fixed again for 5.9—fingers crossed).

This isn't the Frost theme's responsibility to fix but not having a functioning navigation is a deal-breaker. How to handle this in the meantime? Add a bug fix in the theme and test against future WP releases to see when the fix is no longer required? Remove the WP-provided burger/overlay solution and roll your own? These small but critical edge cases all start to add up pretty quickly to increase the maintenance burden for a theme developer.