I often find myself moving between devices. Accessing synced tabs is fairly easy of Firefox mobile with 3 quite natural steps [press New Tab -> go to synced tabs tab -> select tab to open], but synced tab integration feels archaic on desktop browsers.
The best way I've found to access synced tabs is [Reach for your keyboard -> Ctrl-B -> Reach for your mouse -> Click upper left corner drop down -> select Synced Tabs -> select tab to open]. Accessing it using mouse only in the upper right corner menu isn't much better if I'm trying to avoid using the mouse.
All other options in the sidebar drop down have hotkeys assigned to them, and the simple fact that the Synced Tabs sidebar does not makes it a hassle to access it. If it had a hotkey, accessing it would be cut down from seven to two steps [<hotkey> -> select tab to open].
Please consider implementing this in order to make working with tabs on different devices more painless.