Hello Dave
Just tested it and it shows both GPUs. I have a GeForce 3080 laptop and a GeForce 3080 TI.
On performance, I work a lot with Cinema 4D and the render time is halved when I render with both GPUs. So you probably lose some performance from the external GPU, but for me it's still very worth it.

Hi Dave, I have only tested 2 AMD Radeon cards and it works fine and I assume it works for NVDIA too.

But: Due to the low speed (TB3 and PCIe 3.0 (x16)) current graphics cards are clearly slowed down. This technology has been around for a few years now and the price has not gone down (it is currently much more expensive than it was 3 years ago). 3000 or even 4000 GraKas will therefore not be able to develop their performance. TB5 is still to come - then it will be interesting again. At the moment, I would think twice about buying one, given the current prices and the restrictions. If necessary, wait for TB5 (probably coming this year) or consider a desktop PC.

Best regards
Dirk

PS: I mean in the Nvidia Control Panel from the computer/laptop 😉