I think it's more to do with 'filtering'....as in, in DCS there isn't any filtering going on. In FSX and others there is definitely filtering going on which smooths out the input data somewhat. DCS reads the values 'raw'.
On the upside, if you're using Hall Sensors the input is 100% solid.
If you used a calibration tool to view the raw output from the CH stuff, I'm certain you'd see that same jitter. At the end of the day, they're only pots.