Thanks Andrew. That is extremely helpful thanks.
So it sounds like if I don’t want to maintain two hosts, I have to have a .php page with the same name on new host – but that will be outside of the scope of WordPress. And each such page will have a redirect associated with it that will take them to a new page that I can name the same just not having the .php extension. And those new pages without .php will be within the scope of WordPress.
Is that correct?