I fear on Sailfish there will be the same authentification showstopper for a client connected via BTLE like the AsteroidOS client Starfish has hit?
It is ~one year ago now that kido asked Jolla to up the BTLE game but no change(?).

Imo it will never be a replacement until screen and device gets finally separated again. The wrist space is just to small to put more info than Time and Notifications and still be able to read it from sensefull distance. That however i liked when using Pebble and asteroidOS watches.
I only got away from having one on my wrist again since all models i had where uncomfortable to wear or even hurted after some time. Not a watch guy obviously or i simply have not found a comfy one.