A quick update to my previous post. The excessive CPU issue returned and, after some poking around the problem proved to be the NVIDIA graphics driver, which doesn’t play nice with Wayland.
Fortunately, the resolution is simple: You simply need to edit /etc/gdm/custom.conf and uncomment the line that says WaylandEnable=false.
And now, everything appears to be working as expected.
Lightly Seared on the Reality Grill 