It’s not particularly well documented, but it seems like you figured out most of it! Unfortunately, sometimes it’s a matter of trial-and-error to find the right combination (the Jukebox thread has some helpful tips). The SmartThings capability documentation is often a good starting point as well:
Sometimes you have to visit the ‘Proposed Capabilities’ section from the left side menu like in the case of
playPreset()
playPreset() is part of the mediaPresets capability, so I suspect that’s the main change you would need to make.
You’ve already figured out how to find the presets and identify the preset ID, which is great progress. And it looks like you’ve already got a feel for the command and argument format, so great work there as well. I suspect that making the capability tweak should get you pointed in the right direction. 