Ahh.. but Thunderbolt is just a fancy name for "PCIe expansion bus" (plus a few things). So driver support is actually simpler than it might be for USB connected devices. PCI(e) stuff is generally very well supported "out of the box" for most OSs that I know of, so Thunderbolt should "just work".

Meanwhile though, in case you missed it, that USB hub thingie you linked to earlier on, which I originally dismissed as probably doing video-over-USB (aka. "DisplayLink"), appears instead to be using "DisplayPort". Which means it gives you "native GPU" output for one extra monitor.

Cheers