Leonardo Keyboard Library: Support for in-BIOS-keyboard ?

I know this is a very old thread I'm bringing back into life, but I was wondering if anyone has figured out the solution to this?

I have a micro that we use to set up BIOS settings on hundreds of computers in a highschool.

Some models of dell computers recognize my micro as a USB keyboard and work fine in the bios, while other models do not detect the micro.

Inside of windows everything works fine, of course.

Thank you guys!