Androids current firefox application is very limited in capabilities to the degree that one can not even change the backround of the Firefox's homepage to ones own picture.
But their are some improvements I can suggest,
Two different modes, tablet and desktop (/laptop)
Tablet mode leaves Firefox like a typical mobile browser with the bookmarks found through using those amazing three dots, but still has a great focus on swiping shortcuts and more.
Desktop Mode
When a keyboard is connected, a hotkey, or a button within the 3 dots is pressed the browser transforms into a practical 1:1 replication of its laptop version of itself. Meaning more customization, a bookmark bar, but most importantly more native support for androids "Freeform windows."