Accessibility problems, harassment issues, slow emergency escape.
This is literally a non-starter for the international aviation community. No matter how much any one plane company or airline bribes the FAA or any relevant American consumer safety board, no plane with this design will ever be boarded in an airport that wishes to maintain it’s international relationships and customers.
I used to be able to say, “The FAA will never allow this,” but who the hell knows with this admin.