If I'm reading this correctly, "audioplethysmography" is more than heart rate. It's a plot of the actual functioning of the heart, and can detect problems with valves, irregular heartbeat, clogged arteries, etc, too.
I don't know how far you could take it though. Irregular heartbeat in a resting patient, possibly. Clogged artery not in the measurement path in an active patient - probably not. The further from the heart the less and less it looks like an ABP blood pressure wave. I bet activities like jumping up and down would show some amount of interference from blood sloshing around in APG just like in PPG.
If you want to look at some data, https://physionet.org/ has some recordings of PPG and ABP and you can see how they differ. (Edit) like this one: https://physionet.org/content/mimic3wdb-matched/1.0/