I've been running Fx sync ver 1.1 (EoL fall 2015) @home for almost 5 years now on a tiny vm but have not taken the time to move over to 1.5. This requires (since Fx version 32-ish maybe) to keep old installers (ver 28 is the furthest back I go) around for any platform if I re-image or add a machine I want to carry my bookmarks to and then upgrade to latest once sync is complete. iOS _used_ to work but that was the first platform to completely bail on the older sync

This is probably the absolute worst way to handle bookmarking but as long as sync ver 1.1 is still functional I will probably keep doing it, sadly. I've at least given up sorting with folders and labels and just rely on the search in Fx.