Observations:
- Firefox Android exposes a "share tab" feature, but afaict there's no feasible option that would allow me to import them as bookmarks.
- Firefox Android does not offer an easy way to bulk bookmark open tabs
- Firefox Android does not offer a way to bulk open "Synced Tabs" from other devices.
- Firefox for Desktop exposes "Synced Tabs" in a variety of ways, none of which can be used for bulk operations
so it seems that using AboutSync and manually munging data is ... the best? only? approach.
It would be fantastic if AboutSync could integrate the JS bits from this StackOverflow answer in a way that a user can simply export a firefox-bookmarks-compatible JSON of the Synced Tabs of a given device.
https://stackoverflow.com/a/68309779