I’ve got another update on this issue after contacting WD support again for a lengthy time. It seems to boil down to this:
The problem seems to be indeed a TLER-induced problem with these newer drives. Since these newer drives work differently from older drives where TLER could be changed with a tool provided by WD, there is no way it can be fixed in the hard drive itself, which is sadly the final answer to this.
So all that remains now is to try changing things in the boot sequence of the Mac that leaves a bit more time for spin-up of the HDD. I’m not an expert when it comes to this, but maybe someone with some experience with under the hood Mac OS variables and modifying them can chime in here and help out. If that works, I’ll gladly wait a few seconds every time I reboot my Mac. Better than having to shut it down all the time.
