Setting affinity to one CPU core has a barely noticeable difference if that. Why does the CPU usage fluctuate so much? It can go from 11%-45% CPU usage while completely idle?
It can depend on a few things. If chat moderation is enabled, that can cause higher cpu usage. Music tab can also cause it. Basically the bot keeps 2-4 browsers open in the background. One for music, one on the about tab for forums, one for both streamer/chat tab. You can disable a few of them, by right click the cogwheel on the streamer chat tab at the bottom right > Disable. Same with music tab.