Ghosts have v properties that determine their speed. You could tweak that for dynamic speed, however, if you set it to 2, ghosts would start jumping by two squares. Another alternative is you set the Bacon interval to lowest value like 200 ms, and skip moving ghosts at some ticks. In any case you don’t have to dynamically update the Bacon interval, because it’s just a clock. Think about it like a cpu clock.
Thanks for your interest.