GMKtec NucBox5 - Any good? Can we make it faster with NVME?

Some experiments with GMKtec NucBox5, which is a very inexpensive mini PC that can technically upgrade from SATA to NVME.

List of compatible SSDs (these are not affiliate links and they are all unavailable!):
Lexar NM520:
512GG
https://us.amazon.com/Lexar-NM520-512...
256GB
https://www.amazon.com/Lexar-NM520-25...
128GB
https://www.bhphotovideo.com/c/produc...

KingSpec has your 1TB SATA b+m key ssd:
https://www.amazon.com/KingSpec-2242m...

Here are some good tubes about this PC with different review content:
ETA Prime:
The NucBox 5 Is An All-New Super Tiny...

Robtech:
Great RETRO gaming box! ZX01 AliExpre...