Keybow and BIOS

Hi folks,
custom layouts of the Keybow runs very well under Windows and Linux.
However, it is not possible to use the Keybow during the boot process in the BIOS menu.
Is this “behaviour” known and which settings (in Keybow OS) have to be adjusted to make changes in the BIOS menu with Pimoronis Keybow?

I’m far from any kind of expert on this but my best guess is because it uses USB HID gadget mode?
And Gadget Mode requires some interaction with an actual operating system to work?