Love how simple and functional this is.

I tried setting it to home page as well (by using moz-extension://8e7f5414-cebd-884f-af49-f8c0b264770a/bookmarks/index.html as the Help page suggests) but it does not work. It only loads a blank black page.

Edit: Okay I solved it. I opened an A Fine Start tab page > right click > Inspect Element > Storage > Under Cookies there is a new moz-extension ID. I replaced this ID with the path above and now it loads the home page with A Fine Start when I start a new window.

I wish Firefox could simple let people set their home page as a new tab page easily as on Chrome.