I was hoping that I might find a solution to allow this stubborn keyboard to work on OS X.
Varmilo VA87M Mechanical Keyboard - Unboxing & Review
It is from Varmilo, which seems to be a sister company to Leopold, and the board itself may be somewhat related to the FC750R, though it's pure speculation on my part.
I followed the instructions to build the kernel extension here, and had no issues with that. I tried the rake scan process, but it did not appear to output anything accept to the terminal itself, and just to make sure I make sure no existing descriptors folder existed before I ran it.
It identified my mouse and apple keyboard to the screen, created a descriptors folder, but did not actually create any descriptor files.
Seems like this board does not appear in it's list.
Using USB Overdrive I see that the board does show as two completely different USB interfaces, one with 49 programmable keys and the other with 48. Nothing on the board functions at all when plugged into either of my Macs, which are a mid-2012 mini and Macbook Pro).
This also includes the controls for non-host things like the back-light.
One thing I did notice that was interesting is that on my Macbook Pro I have the full disk encryption enabled (FileVault). During boot where it asks me for my password, the keyboard does work there, which I believe is in the land of EFI.
I have also been told that the keyboard works in Linux, not that that's much help I'm sure.
Your thoughts, and suggestions are most welcome.