OWC Mercury Elite pro

In Activity Monitor>Show all Processes, does fsck show as active?

Have you checked with OWC?

I have two Elite Pros on my 2017 iMac 5k and an Elite Pro Mini on my Macbook Pro. They run very quietly while the computers sleep.

I have zero concerns with this. I have my computer set to create bootable backups at 4AM every morning via Carbon Copy Cloner. If the drive is off or disconnected, this does not happen. Time Machine also works during the night with these drives.

For me this is a non-problem. It would be if I had cheap enclosures with cheap drives inside but I don't.