That's fair and the extension is not for everyone. It's not really meant for saving sessions or anything like that it's more for finding lost tabs in a sea of windows like I typically have. This is more for tabs that are not worth saving to bookmarks but that you have open for a long time as a transient bookmark.
FWIW, Mozilla looks at all extensions before fully approving them and the app is fully open source and fairly easily vetted if people are worried about that sort of thing.
Thanks for the feedback!
Anyway I used an extension like this for awhile, called session buddy. But now I just use control+D and bookmark all my tabs. Then you get bookmark syncing, and you can save your tabs when you export bookmarks, or wget them to have a local archive, etc. It's just more convenient, and one less extension I have to worry about stealing my personal information or bugging and corrupting my data.