Rated 4 out of 5 stars
it seems that the add on only uses the icloud keychain. is there any option how i could use both the login and the icloud keychain for autofill? also i would like to tell the addon whether to save a new password to the icloud or the login keychain
It should use your keychain search path, which should be the same order as the list you see in the top left pane in Keychain Access (you could confirm by running "security list-keychains" in the console)
There are two undocumented preferences, which I use mainly for testing:
extensions.macos-keychain.search-path - a colon-separated list of keychain paths to search for passwords (overriding the system search path)
extensions.macos-keychain.write-file - the path to the keychain where passwords should be stored
You can set both of these by going to "about:config" in Firefox
The problem is that the Local Items keychain used by iCloud isn't stored as a keychain file and doesn't seem to show up explicitly in the search path, so this may not give you exactly what you want. But it might let you find a workable solution.