So cloned voices via the free plan are not accessible via API?

I inputed my credentials here to list cloned voices but the ID provided was just to a stock voice: https://docs.play.ht/reference/api-list-cloned-voices

I couldn't see any other way to access the ID for my cloned voice, which is a shame and would be useful whilst testing and building.

A lot more documentation would be good, eg what audio format is the response via API given in in sample rate etc? For cloning a high fidelity voice on the upgraded plan should we upload .wav or is mp3 essentially equivalent? Where one cloned high fidelity voice is allowed, can this be re-analyzed until it's right or we just get one shot? The documentation is rather limited from what I could see. I've had to do a lot of guessing and trial and error in coding to work it out.