Absolutely no prob for my time! I even also thanks you! because you have made me learn so interesting things about manual reading/writing modules, and even in CHS, Wow!

This is my right buffer: 0C 00 02 00 67FFFFFF 01 00 BD 05 5A 00 00 00

And I get an automatic script to generate your SMART, so it was easy this time... but damn I'm always unable to customize those raw attributes... hope a day I will finally success... try coming back later for your hours update!

Note to self: When using a throwaway Windows on a computer with very old mechanical drives, disable Windows Defender and Windows Update. When I started the old machine, this stupid Windows 10 decided today was a good day to strangle the system drive nearly to a halt by downloading a major update and scanning for viruses at the same time...

So I tried the "Clear S.M.A.R.T." feature on the WD Green.
Before:

After:

Amazing! This drive now looks completely brand new! Until you actually start using it, then it dies.

So I (finally!) did the same with the WD Red.
Before:

After:

And after putting it back in the NAS and executing a SMART test... The disk is reported as "healthy"! No warning! IT WORKED! YEEESS finally! The NAS also reported in the SMART history "-16" errors, but I fixed that by connecting to the NAS with Telnet and doing a "sudo vi /var/log/disk_overview.xml" where I zeroed the old values in the "<retry>" tag for the drive. So all is good now! Now my NAS still performs SMART tests, but without needlessly alarming email notification asking me to be wary of my perfectly working WD Red.

Again thank you so much for your help!

Does the latest version of wdmarvel do the same? Or can you share your version?