According to the product page on Amazon, the Pixel 3 is also supported.
However, it is best to ask the manufacturer directly whether the information is current or correct: https://www.woodcessories.com/ladestatio...
Unfortunately I can't answer the question because I use the EcoPad for my Apple-Natel, which works very well. But I think if the Galaxy Watch supports inductive charging, it should work (don't know the Watch, therefore no guarantee ;-)