Will RX 580 based e-gpu work on High Sierra 2015 MBP?
Yes, it will. Unless you want to future-proof with a Thunderbolt 3 enclosure, a Thunderbolt 2 eGPU enclosure will work fine for a 2015 Macbook Pro. Also, your AMD RX 580 is the perfect card to use with macOS. Plug-and-play. Good choice!
Thank you! I want a Thunderbolt 3 enclosure to futureproof my build.