Improve Firefox Sync integration

[codedpalette]

I've been trying Zen Browser with Firefox Sync to sync my tabs between desktop and mobile. It mostly works, but there are two things I would like to improve

1. When having tabs open in multiple spaces with different profiles, Firefox Sync lumps them together on another device. Would it be possible for Zen to essentially fake multiple Sync devices, so that vanilla Firefox would treat Zen spaces as separate tab collections?
2. Pinned and not pinned tab are mixed together, which is kinda frustrating, especially coming from Arc Browser, where there is a clear separation between them on mobile apps. Maybe we could implement config options to configure pinned tabs syncing as regular tabs/through bookmarks/or disable them at all?