eGPU for Ultra 4K Settings

I am currently using a 15” MacBook Pro 2018 for Zwift. I can use the ultra settings with 1440p.
My question is if I am using the black magic eGPU sold in the apple stores, can I use the 3840x2160 settings?
Or even more general: does Zwift on macOS use an attached eGPU?
Thanks for the help!

The current Blackmagic box has a 580 in it. Not a huge improvement over the 560X. I’m waiting for the Blackmagic pro with the Vega 56 for measureable improvment

Hi Cameron,
I was also thinking about the Pro version. Do you think you can unlock 2880 Ultra setting with that?

I’m not sure since there aren’t any Vega 56 benchmarks in

I would think the Vega 56 eGPU would def get you good frame rate at 2160 Ultra