Re: Really bad FPS lag with ISboxer.
I tried hyperthreading on/off in cpu strategy, seems to make no difference.
Your CPU doesn't have HyperThreading, it's just 4 cores. As the option says when you click on it, what this actually DOES is make the CPU Strategy double up on the cores. This is only relevant if you are selecting the Round-robin CPU Strategy. Since you're now picking the the All windows All cores setting, this means the HyperThreading option is expected to do nothing. In your last paste, your CPU cores are fully utilized, so that is fine. Your GPU is still available for more work though.
I have attempted to lower the texture quality via the games Ini. Basically it makes the game look like a potato. Even with that still hitting 100% cpu...
Texture quality and other graphics related options will mostly reduce GPU load rather than CPU load.
Your best bet might be to disable/lower non-graphical options in the game, or alternatively to purposefully lower your maximum FPS, particularly for background windows.