Are eGPU's supported in os x Mojave running Windows using bootcamp?

I just updated to Mojave, and I own a macbook Pro 2018 (Intel Iris Plus Graphics 655) on which I ocasionally switch to windows using Bootcamp to play Overwatch. However there is some issues with the intel iris graphics while running Overwatch (rendering device keeps beeing lost after some playing, overheat or some driver issue - would be nice if Apple would look into this issue- seems hardware/driver related). I wanted to fix this by using a eGPU in windows using Bootcamp, but it would be kind of a waste to fork out a load of money for an eGPU if it doesn't work in windows using Bootcamp.