Thanks for the quick answer. Does that apply to all tablet vendors? We are also looking at Panasonic Toughpad fz-g1 and those don't even function with the on-screen keyboard. Assuming that is a Panasonic issue as well or could that be within the Preboot area?
The OEMs choose to implement or not the Absolute Pointer Protocol.
I have seen instances whereby the OEM decided only to implement the APP if their BIOS screen is called, others where they implement the protocol but do not bind it to the hardware and finally others choose simply not to implement it at all.
My best suggestion is that during the procurement process you ask the OEM to validate if they provide the protocol and if they are selective in the way they provide it, alternatively if you have access to the hardware you can run our tablet compatibility tool (available here) from a USB and from the hard drive itself, if it passes in both cases then the APP is provided.