The charging adapter that comes with the watch fits tightly in place without the need for any glue or magnets. The final print with the watch in place is very stable and balanced so as to not easily topple.

This prints without support. 

NOTE: It is not necessary to press the charging pad completely in, once aligned slightly press in on the edges to gently seat. V3_PH contains a hole behind the pad insertion location to assist with removing the charging base.

This is a final working watch stand, I'm iterating through enhancements to incorporate a Pixel Buds and Pixel phone charging ability as well.

NOTE: I've received a comment about receiving a “misalignment pin error”. Initially I encountered a similar situation. If you situate the charging pad so that the top is pushed in ≥degree greater than the bottom it will work. I will modify the model and upload a revision