Was able to get it running smoothly using DxWnd on Win 10 64bit
https://sourceforge.net/projects/dxwnd/
Tips:
Use a fresh install (No compatibility settings enabled on game.exe or nox.exe)
In DxWnd, start by Importing "Nox (GOG).dxw" from the DxWnd Exports folder
Modify the new profile
"Path" = your actual GOG\Nox\Game.exe
enable "Hide desktop background", "Keep aspect ratio" and "desktop"
Switch to the "DirectX" tab
Change "Renderer" to OpenGL (Important! Don't skip)
enable "Full bilinear filter" (If you like graphics smoothing)
These settings should allow you to run the game in a borderless fullscreen mode, though text will be a bit blurry. You'll also be able to up the graphics resolution in game if you wish.
If you'd prefer being in fullscreen 640x480 only (larger resolutions don't seem to work) for the crisp text. Change the following in the DxWnd profile, at the main tab.
disable "Run in Window"
enable "Fullscreen only"