I disliked the pinned tab behavior, so I created this extension to overwrite the behavior to my liking. Do note that this extension overrides default pinned tab behavior.
Usage: go to "about:addons". Click on the "Startup Pins" addon. Go to the "preferences" tab.
Add the urls you want pinned at startup.
Known issues: "about:" tabs do not work with this extension. These can be pinned in the regular way and the extension will not override this behaviour.
