As promised, here are some results.
Mid-2015 15" retina MacBook Pro
OS X Catalina
Sintech short black NVMe adapter
Sabrent 2TB Rocket Pro
Link width 4
Link. bandwidth 8.0 GT/s
Benchmarks - Roughly 2400MB/sec write, 1900MB/sec read
I have open and closed the lid numerous times, and the Mac came right back as expected.
I have let the Mac sleep for 3 and 12 hours, and the Mac came right back as expected.
No hangs, no black screens, no kernel panics thus far - which is in its second day of testing.
I am confident enough in it to have screwed the bottom case back in. In hindsight, I wish I had not yet, just to check some more on the Silicon Power 2TB NVMe, which repeatedly hung up and crashed.
The only difference I see between the Sabrent and the Silicon Power is that the Sabrent revision is ECFM12.2 where the Silicon Power was ECFM12.3
So perhaps that different drive firmware is the problem with the Silicon Power?