I ordered the product with 16Gb of RAM. In the package, there are two adaptors for SATA ports. I installed an old 120Gb SATA SSD and flashed TrueNAS. It booted from the first try, without any problems.
It would be nice to have a way to get the SATA adaptors outside in a better way than punching a hole in the product label and provide some usable thermal pads for the NVME ssds. But other than that, I have nothing to complain about the product. Another improvement might be a better way to cool it down. With 4 NVME SSDs, I think it needs active cooling during the hot summer season.
My package arrived very late, by my standards and the box was punched. The product case was touched by some metal bar or something similar, but the stability or the functionality was not altered.
Until now, I have to admit that I like the product and that it fits the purpose.