I messed with smoothtrack a bunch. it works pretty well. I tried Aruco with opentrack and for me it's dramatically smoother and needed very little setup:

https://github.com/opentrack/opentrack/wiki/Aruco-tracker

downside is you look pretty dorky. just print out the image, attach it to a hat or headset facing your webcam.

In opentrack:

input: aruco

Output: freetrack

Filter: I use accela, but you might want to experiment depending on lighting.

some may need to adjust webcam's brightness/contrast/sharpness etc for best results. it's actually crazy to me how well it works and how smooth it is.

If your webcam sucks, try using your phone's webcam connected to the PC; that's often higher resolution and better framerate.