this is generally expected. Almost nothing can be modulated/automated/updated perfectly smoothly --- other than of course via our own internal modulation.
whenever something is updated there are pretty massive calculations that need to be recomputed, and they change in non-linear/non-continous/discrete manners, so continuously automating Position for example is not possible to do smoothly (again, other than via our own internal modulation).
What you can do is to single click anywhere in to Position Display and the Angle and Distance parameter values will jump to this location and there will be only one update, with a very small click -- almost inaudible. This will feel smoother than dragging the pos display around (as this causes many updates to happen as quickly as possible, each one resulting in a small click, so if we have 10 or 100 small clicks per second, this may sound like stuttering)
maybe in the future we would consider trying to make a version that allows full automation of the position for special effects like doppler etc that could be cool for film/tv/game sound FX... this would likely require 4-5-6 times as much CPU though... That's not the goal of this first version.
great. thanks.