Vt-d gpu passthrough on T430 with egpu

Good day,

I recently had the opportunity to swap my 3630qm for a 3740qm, the latter supports VT-d, which got me thinking. I use an external PCI-e adapter to connect a gtx 970 to my laptop via an expresscard (pcie x1 gen2) interface. This works fine in windows, even when using the internal screen. Would you help me by clearing a couple of things up?

First question, could I use gpu passthrough to drive the internal screen? I know that it works when using an external screen, if need be I’ll just dual boot when on the go. Would be neat if I don’t have to though.

Secondly, I’m planning on getting a modified bios to add 400mhz to the all core boost clock, this also requires a program like throttlestop iirc. Could I allocate 3 cores to the windows client and overclock them from there? I configured my linux distro to use as little power as I can make it, and I’m not sure how to change the boost clock multiplier in linux tbh.

Thank you in advance