Hi Paul,
I have a Surface Dial now here. I did not have much time, yet, to muck around with it, but the most basic stuff I did with it so far did work for me.
So I set up a custom tool and mapped ctrl + page up as Fast Forward, ctrl + page down as Rewind and space as Start/Stop (of course made sure that the keys match with the commands in the Dorico Preferences) and yes, works beautifully for me.
Maybe you can explain in more detail what you are trying to set up and what does not work with you.
Cheers,
Ulf