That's really unusual - the 4tb MyBooks typically have white labelled WD Blues in them. I broke off a couple of winbond chips off the mybook PCBs to support smaller drives - works a treat but you can only use them as basic external drives - you can't use the WD mybook software to schedule backups/encrypt data on them.
I haven't put any in my Synology but the cheapo startech caddy drivebay thing I had works fine no mod needed. https://www.servethehome.com/wd-red-smr-vs-cmr-tested-avoid-red-smr/2/
From a mixture of approx fifteen MyCloud, Mybook and Elements drives, ranging from 2TB to 10TB, I've never had to mod anything to get them to work in QNAP/Synology NAS boxes or Windows/Linux PCs. They've all just worked.
Not at all, it's often vastly cheaper. Same kit, bit different addressable market. There's an element of binning as well undoubtedly, and it also allows manufacturers to consume surplus manufacturing capacity more easily.
That's exactly it ... of course it's all a bit up in the air with the SMR drives that the disk makers seem to want to sell all the time now.
I bought the WD offer for 171 for 12tb, no bare drive cost come close. 1) sure it's pot luck on disks but 8tb and above currently seems safe from wd smr shenanigans. 2) lose the warranty, again given its in an array I'm looking for the cheapest option. Also if shucked right you can reassemble if needed.
