Hello all. Long time egpu.io stalker, but rather new poster.
I got the 2018 macbook pro back in august and got the dGPU and eGPU working together (it drove me nuts that they didn't work oob). I wanted to post a guide but figured that I didn't have much to offer. Then today I got bored and posted the guide I started months ago.
Hope it helps.
2018 15” MacBook Pro i9 32GB 1TB + AMD Radeon Pro 560x + 550w Sonnet breakaway + AMD Radeon RX 580 + macOS 10.14.2 & Win 10 (1803)