So, i've been using the following expression (pasting a "short version" of it) to add automatic behaviors to the start/end of a layer, at properties such as opacity.
Now, I had this idea of applying the same expression to the "end" property of a trim path animation. And it does work. Except that... For some properties (e.g. position), I like to shape my speed like this:
And the built in "ease out" function produces nothing of the sort. So, researching over the internet I came across this magnificent site: