System specs (Mac mini 2018, i3-8100B 3.6Ghz 4-core, UHD630, GT740, 10.14 Mojave)
eGPU hardware (Highpoint rocketstor 6661A, EVGA GT740 2GB DDR5, 6-pin power from Corsair SF450, LG 43" 4k TV)
Installation steps (what did you do to get it all going?)
plug eGPU into TB3 port on login screen (didn't work if plugged in at boot, however after first time could work permanently plugged in).
Benchmarks (only tested in Unigine Heaven 4.0 Basic 1280x720. UHD630 fps 23.2, score: 585 GT740 fps 51.0 score: 1285)
Comments (full metal support, working well with stock Apple driver, color depth didn't look as crisp as UHD 630. Nvidia web drivers did not work and black screened with no hardware acceleration with direct connection to TV.
Note: used EVGA GT740 has almost identical spec to GT755m used on iMac so I presume that's why it worked (almost) OOB). Edit: GT740 mini-HDMI to HDMI cable used to connect to TV - no sound thru HDMI, external speaker used.