I'm trying to expand an element's height from 'auto' to '100%', and reverse it. By just using `to()` percent height, there's a slight jolt in height due to percent-to-pixel rounding. So in order to circumvent that, there was another post that suggested to predetermine the heights before starting the tween.   The two issues I'm having right now are: Timeline is compiled ahead of time, but I thought the whole point of a property function was that it was executed during runtime (def