I was wondering if it is possible to add an intertial bounce to the the path property of a shape layer?

I have a shape layer with one filled path within a group, I have animated the path property of this shape to grow and want to add an intertial bounce (or any bounce) to this growth. When I try to add the expression, I receive the error "After Effects error: can't compute derivative to a non-spatial custom value ( 29 :: 57 )".

I did some digging and could only find

this thread about using expressions on paths, and am wondering if there is a way to make my path bounce via expressions.

The expression I am trying is from

here, and I've included it in the post as well. Thanks for any help!

`amp = .1;`

freq = 2.0;

decay = 2.0;

n = 0;

if (numKeys > 0){

n = nearestKey(time).index;

if (key(n).time > time){

n--;

}}

if (n == 0){ t = 0;

}else{

t = time - key(n).time;

}

if (n > 0 && t < 1){

v = velocityAtTime(key(n).time - thisComp.frameDuration/10);

value + v*amp*Math.sin(freq*t*2*Math.PI)/Math.exp(decay*t);

}else{value}