T400/T500/X200 are really similar.
The following applies:
(for vt-x to be non-bogus, microcode updates are needed, which libreboot won’t provide. Osboot could. For vt-d2, that extension just didn’t existed. So sys-net and sys-usb will not provide strong isolation).
Not sure of 4.1 behavior of Qubes installer. It will sure complain that the hardware is not compatible.
Not sure if installer permits to proceed anyway, if it does, not sure if sys-net nor sys-usb qubes creation will succeed.