Hardware Security - Intel up?

[12491'0'410'401'401'424]

Hello,

there exists FPGA USB sticks:

http://fpgablog.com/posts/avnet-microboard/

Which might be interessting for some shielded functions, like private key operations and can improve the Qubes OS security layers.

But why you turn it not upside down and run an harded FPGA with very limited features for the dom0 and all security relevant code, which is quite limited.
And than you connect the Intel-Board and run it inside a QVM?

What will be the Pro and Cons?

Kind Regards