https://www.roland.com/us/support/by_product/dif-at/updates_drivers/86187843-8227-4307-b9f5-246ffcc7e27f/ (windows)
I have not yet performed a Diff of my firmware and the midi updates. I would have to reconstruct them first into a full image. I think my firmware is not corrupted though at this point. I will try and send the DFU command and the payload using a python script instead:(see below) The midi files are 4x33kb. Minus headers etc; 32kb actual payload x 4 = 128kb firmware. A 512kb NOR flash is generous space for this (4x bigger) Though remember its banked for DFU (when the update is written and verified it will switch active bank flag) Also it seems remapped to different addresses in runtime operation also. There are plenty of 0xFF regions though, so not everything is written with instructions.
===DFU Python Script===