Here’s what I found on Windows.
I tried pm.sample(mp_ctx="forkserver") but I got ValueError: cannot find context for 'forkserver'.
The other option, pm.sample(mp_ctx="spawn") didn’t work either. I got the freeze error on that one.
On any of my Linux systems I find that this is entirely a non-issue and don’t have to think about it. 
Unfortunately I am required to use Windows sometimes.