Did you find a fix for this? If not, what I have found that works for me is to change the Vsync option to either adaptive or adaptive 1/2. It takes my GPU usage from 99% all the time to 60-80%, the only downside is that because you're using some form of Vsync, you'll have more input lag. One way I have countered that is by using this software called TimerResolution which basically reduces the reaction time from 1ms to 0.5ms which probably varies from monitor to monitor.
I hope they actually fix it though... one day. Been having performance issues with this game ever since it's been out.