Final Cut Pro X 10.3.4 Supports eGPUs →
Apple Support:
Get improved graphic performance in Final Cut Pro X with an eGPU. Either connect an external display to an eGPU, or use the Prefer External GPU option in macOS Mojave.
Finally!
eGPU
Are External GPUs for Macs Viable in macOS 10.13.4? →
Samuel Axon, writing for Ars Technica:
We tested an eGPU enclosure with a Thunderbolt 3-equipped MacBook Pro, and found that, in most applications, performance didn’t disappoint. Unfortunately, we also found limitations and software support inconsistencies that prevent the Mac eGPU dream from being fully realized at this time.
This is an extremely tempting solution. I imagine my current setup changing from a Hackintosh and MacBook Pro 13” to just a MacBook Pro 13” with a eGPU setup and external monitor. There would be a few caveats: I’d need a 2 TB SSD in the MacBook, at least a 4K monitor, preferably supporting Display P3 (my current 4K Eizo is sRGB), and I’d want one of those new quad-core Core i7s from Intel. They’re already available but Apple hasn’t yet ingested them into the lineup.
That and a reliable keyboard — my MacBook Pro is currently in for service for a new one.