I just pushed a first version of my open source editor for the #HarleyBenton #DNAfx GiT devices. It was my first attempt to do USB reverse engineering and use libusb, so although it's currently limited (there's more I want to do), I'm already happy with what it does.
https://github.com/lminiero/dnafx-editor
At the moment, I can connect to the device and download/convert/upload presets, which is what I needed. More tweaking capabilities and more control interfaces will follow in time!
