Can the Teensy currently act as both a keyboard and a MTP device at the same time? I've got a Teensy 3.5 device and I want to it send keystrokes to a device and then afterwards send a file from the SD slot to a device. I noticed when selecting the USB type, that we only have MTP or the many keyboard types but not together. Is there some development on the Teensy that I would need to do (like defining such a device in the library) or am I not using the correct Teensy board?