Pine64 is also developing a smartwatch – PineTIme if I remember correctly. The fact that it’s an open device changes everything compared to all the other devices out there which are completely locked. I might get one once it’s available and more polished in terms of software.
As for Pinebook Pro, I heard they would do an hardware upgrade sometimes soon (2021?) with 8GB of RAM and a beefier SOC. That would become very interesting.