Yeah, but this came out at the last WWDC, I think - https://developer.apple.com/development-kit/external-graphic...

I believe Nvidia drivers are already in beta, this or any other eGPU enclosure should be able to remove that sticking point.

There is a slight performance penalty because fo the TB3 bus conversion bus, but it's only applicable for real time work like gaming - pro work should be able to use Nvidia cards just fine.