[Update 5/6/15 16:30 Uhr:
One of the closed tickets at the Func support was re-opened and a comment added! Check it out below!]

In the light of current events I have to issue a warning to all those people, who think about buying the Func KB-460 keyboard. This keyboard seems not to be an USB HID compliant keyboard!
I bought it because of the technical specification and the retro looks and tried it on several PCs, it only seems to be working OK as soon as the windows drivers are loaded.

You can NOT enter any BIOS/pre-boot passwords (random keypresses are detected etc) and my tests with Linux where also negative. It seems as if it is good hardware with a very crappy firmware. Contacting the manufacturer support was also very negative:

Support info (quotes!):

„[…] but we designed the keyboard with N-KRO (N-KRO means the keyboard can register any number of simultaneous key presses, while regular USB keyboards have a max of 6-KRO, or 6 simultaneous keys.“

[comment: for those people with more than 10 fingers or who like to slam the head on the keyboard while trying to get it to work]

„Our KB-460 achieves this by registering many keyboards connected to the computer (you can only see one as they are registered as a “Composite Device”, or a “device with more than one function”) and the BIOS is unable to make sense of the input coming from the keyboard.“

Several cheaper n-kro keyboards offer the possibility to disable this crap. Here is what the 90 EUR / $100 Func keyboard can do:
„I am sorry but Func KB-460 does not have that kind of function. You cant disable n-kro.“

Yes. Nothing.
[Update]
And here comes the surprise. After publishing this article on 5/6/15 around 2pm, 2h later I received an info from the Func support into one of my „resolved“ tickets:
„Seems like the KB-460 has an undocumented function.
Press FN+N and it will disable/enable Nkro.
This function should not be there. But it is.“
It shows, that using FN+N to disable n-kro seems to solve this problem.My BIOS now shows only 1 connected keyboard.
Give it a try!