The product pages mention custom payloads, in some of the images it looks like some variant of the DuckyScript used in some of the other hak5 products. It likely depends on if what you want to do is supported or if it would need changes to the firmware to accomplish.

They sell a programmer for it, so probably!

Interesting. I'm not sure if that is for pre-programmed payloads or not

As was posted in a separate thread, you might look at http://tomu.im/ too

Those are pretty cool. One of the big use-cases for me is small-form-factor USB-passthru sniffing, however. I don't think any of the Tomu devices have that but would definitely be an option if so.