I was poking around in TaskMan, and I noticed that DF had an Affinity for just my first CPU core, and a priority of Normal: Can I ask about the cause and effect of these settings?
On some machines, we were running into threading issues when DF was set to use all cores, so we've set the default to just use a single core. If you'd like to try running it on all cores (I do on my machine without issues), you can change the CPU Affinity option in the DisplayFusion Settings > Advanced Settings window, then restart DF
If you run into issues, you can just change it back and restart DF again.