Chas, you load in new sounds by USB means you can get .wav's of drum sounds, and load them in there. Whereupon you have to map them, stack them, x-fade them yourself. So, if you have BFD, you would have to pick certain samples, export them (you realize that BFD has dozens of samples per note?), import them to the Alesis, assign them to the note you want them on, at the velocities you need them at, and slowly build up a kit like that. No different to doing it on your Korg, really. How much RAM can it hold? Those BFD kits take GB's

Alternatively, you can use a laptop to actually RUN BFD (or a desktop, or Receptor, etc.), then use the USB to MIDI into the laptop.

In neither case is the Alesis actually RUNNING BFD.