Addons have to implement their own ways to backup and import data, it can be very tedious to do so when using multiple or switching profiles. It wouldn’t be possible to just copy and paste profile folders, like from Firefox Nightly to regular Firefox (since the Firefox version is too new), from Firefox to Floorp, or vice versa for both.
What if Firefox had a built-in UI for exporting addon data, either for individual addons or multiple bundled into one file. It would be a convenient and reliable way to keep addon data outside of the browser, as well as just exporting one file with all addon data from one Firefox instance to another, or for individual addons if u wanted to. But would that be possible? I mean Firefox has to store addon data somehow and it could bundle all the data into individual files.
As an independently developed tool, I bet it already exists.
I don’t think things would be purpose built to allow it in Firefox, or the line between backup/restore and synchronization would start to blur, and that opens a whole new world of problems.
Firefox sync already supports syncing extensions configuration but it needs to be explicitly supported by the extensions.