Hello Mat Brady,
Welcome to Microsoft Q&A forum.
The Windows 10 Pen & Windows Ink settings will only show extra option if it detects a native pen device, which a Wacom pen is not. To control pen pressure, Wacom tablets usually use their own Wacom center or Wacom tablet properties, since this is monitored by the Wacom driver. Can you please check if the pen pressure works there?
I hope this clarifies.