This is beats anything out there currently. A few suggestions are load the notes current to the website or page instead of all of them showing or at least move the ones create from that page to the top for east editing. Other than that I hope that you continue to update this!

By far the most functional simple note taking add-on I have used so far.
Not great but good enough. It does it's job and doesn't delete notes randomly so 5 stars to support it.

The layout is not that great, I would much rather have a list of notes and a preview area beneath it in a side bar than note occupying entire sidebar when clicked.
Also the list doesn't get updated with a newly taken note (from a web page by context menu) until you "refresh" the list by entering and exiting an existing note.

This is the best Notes to find so far. There are a few details to find out.
A few suggestions for you:
1. Middle mouse button to open a new TAB or window for editing.
2. Lighter dark theme.
3. Hopefully, Firefox mobile will be supported in the future to ensure synchronization is not lost.