I have several extensions (1Password, Firefox Relay) which enhance form field functionality. I also rely on the browser's form fill behaviour as well. (I love that it will suggest previously used values when I fill out a form for a second time).
These different tools end up "fighting" for the input field (especially for email addresses!). Several want to add their own icon to the field and then when I try to type in a field I get multiple over-lapping drop downs. It would be great if the browser could facilitate these interactions.