Its not perfect, but it is well thought out. You don’t need to leave the app as you have both the styles and instrument sounds within the same app.
I would like to see capability for playing user styles (.sty), but I don’t think that makes sense for OMBs business model, so I am not holding my breath.
To make this a performance tool, please consider some type of midi sync, eg Ableton Link. Also for future updates please consider adding the ability to play Audio Units withing the app.
This is a good start however.