The problem: there are corner cases where the popup is not in sync with the current tab. This means that the operations prompted through the popup can be potentially be performed on a wrong url.
As an example: changing browser tab with keyboard shortcuts keeps the popup open while also changing the "current tab url".
Possible solutions:
find a way to close the popup when changing tab with keyboard shortcuts (and for all other corner cases)
move the popup icon from the tool-bar to the url-bar (e.g., near the bookmark start)
Each version of the addon can require more data and/or can change the format of its config data.
We are missing the whole infrastructure to manage such changes. Indeed, we need an "entry point" that fetches all the config data and that could perform some versioning (otherwise we could end up having some data formatted as per version X.Y and other data formatted as per version Z.W)