If I recall, people were thinking somehow Microsoft whitelisted version and 2TB/1TB/512GB capacity via firmware too. So even if you found a drive that operated x2 lanes, you'd have to stay at or under 2TB and spoof the drive potentially (EEPROM write somehow?).

The weird thing is Seagate was the one who sold the drives. Here is a teardown.

Now WD is coming out with an expandable drive (here is a Best Buy link that was pulled).

This is the adapter I've seen used. I'll check out your server. Thx for mentioning it I didn't realize you had one.

And awesome on SSSTC. I read the TweakTown Tiger Shark Gen5 article. Tried to research the drives a bit more (e.g., 2TB is Model TS2TB-26 SKU: SSTC-PHI-E262TB). Found the company that sells on Amazon (Long Ha) and the distribution company (SSTC Technology and Distribution). Would be interesting to get more info on release date or if it's been release elsewhere in the world.