I'm afraid there's nothing I can do about it. It's just the way Chrome renders the animation. If you inspect the element you'll see that 2d position is being set correctly, without any jumps. The jumps are most likely caused by the differency between x and y, where for each
1y you'll have
0.2x. Translated to pixels, this would mean that for each 1px moved to the left or right, you'll have 5px moved to to the top or bottom. When moving pixels around, it can only get as accurate as the browser decides it can get (as an example, rendering 0.5px will be "forced" by your GPU and cannot physically exist on your monitor).
Being progress based, imagine will render each frame as many times as it can, but it can only move things around as much as the browser allows it to.
Try to play around with the values and see which ones will be good for a transition without jumps.
However, I'm impressed. I haven't tried applying such a workload on imagine. The page performs extremely well given the number of animations!