I was outside my garage lifting weights today; and I was running an "Einsteinian thought expirement"
in my mind regarding the speed of planetary rotation, and the "slingshot effect". Namely, anytime said effect is used, the rotational speed of the planet changes, either increased or decreased. Basically, the line of the thought expirement that occured to me was that if a galactic tier civilization decided, for whatever reason, to use said effect to increase the rotational speed, using the star it orbits as a reference point, what would the effect on the planetary body, both gas giant and rocky, as it's rotation speed increased, per order of magnitude of speed increase in relative rotation?