The question cannot be answered with 100% certainty. I would definitely not operate server hard disks that run continuously in a fanless single enclosure. But the enclosures are fine for archive disks with low power consumption and heat dissipation. For server disks like the RED, it's better to invest a little more money in an actively ventilated enclosure. In addition, it also depends on the installation and the air circulation at the installation site.

I have no problems.
Use the enclosure with
Seagate IronWolf, 10TB
However, no continuous operation.