Greetings from Boston
Thanks particularly to ricosuave0922 for the help. I'm on a Macbook Pro, mid-2015, running High Sierra, with an AMD Radeon R9 M370X internal running an Apple Thunderbolt Display; and a Sonnet eGFX box with an NVidia GTX 1060 externally, powering 3 23" VX2452 displays, giving me 4 monitors across a 5' panorama. Great for work.
Had issues with the driver until the most recent Webdriver and v3 NVidia eGPU support script, and I still have to power the laptop, get to the boot screen, and then plug in the eGFX box. But the GTX 1060 is powering everything and giving me great performance.