So in preparation for DOOM Eternal, I decided to boot up DOOM again for the first time since the update, and was met with an unstable framerate that made the game unplayable. I have a very good computer with an i7-6700K and GTX1080, so you could imagine my frustration when the game refused to run perfectly, especially since it had in the past. I spent probably around 2 hours fiddling with settings in-game, Nvidia control panel, drivers, and even reinstalled the game, until I found an obscure community thread that held the answer amongst all the other nonsense that goes on in Steam discussion forums. I wanted to make this guide to hopefully bring attention to the issue, because it was so small and seemingly insignificant it blew my mind.

Go to Settings > Mouse and Keyboard and uncheck Razer Chroma.

All my performance issues were solved after doing this.