It’s elk. https://github.com/elk-zone/elk

This isn’t true. The bootloader and boot process will be the same. This link is about the bundled Chrome (which is also what houses the entire UI/UX for the OS) becoming deprecated as the main browser for the standard Linux flavor one running through the wayland bridge of Crostini.

Firefox Beta as well.

There is a hidden way to activate more extensions and most - if not the vast majority - extensions work fine.

I got my invite a couple weeks ago, so they have definitely been working down the wait-list.