I'm having similar issues. Framerate of about 1 frame per second. I find that the game is using less than 10% cpu and less than 200MB ram. Windows 10. Geforce GTX 1060 or thereabouts. The lag begins only after the unity logo (in the game). No command line output.
At this point I'm inclined to believe this may be due to the specific unity version this was built under, since it's only effecting specific devices. I'm not really certain what the solution may currently be sorry, and am unfortunately not really in a position to explore this further at the moment either