UGen rate of change

Is there an easy way to get the rate of change of a UGen? Can think of some fiddly ways of doing it, but feels like someone must have done it before
e.g.

(
{
	var wobblyFreq = 440 * 1.5.pow(LFNoise2.ar(5)); //what is the rate of change of this?
	SinOsc.ar(wobblyFreq)!2 * 0.1
}.play;
)

See Slope.ar/kr - Slope | SuperCollider 3.13.0 Help

Thanks, thought there would be one