Lightning to VGA Adapter + USB flash drive?

Hello,

I have the Lightning to VGA adapter, and works very well for simple presentations with my iPad mini, but I need to use many (>20) and heavy (>50mb each) Keynote presentations to teach a course, and I was wondering if is possible to put these files in a USB flash drive (like this: http://www.adamelements.com/web/products/detail/168/c), and then connect that drive to the additional lightning slot in the adapter (that originally reserved for charge) at the same time the VGA slot is connected to the projector, instead just transfer the files to my device and using my internal storage to project them.

I know that some of these USB sticks have companion apps to browse the files and I should pay attention if this can support .key files (as well as mp3, pdf, etc.) but my main concern is about using the adapter to connect the VGA cable and the USB stick at the same time.

Thanks in advance,

Farid.