Hello,
First of all thank you for the hard work in this forum, I have already read many topics he regarding this, and also found some knowledge.

Basically my goal is stated in the topic subject.
I currently have bought a PCIe adapter with 4 nvme slots in aliexpress.
As expected when I bought it, the adapter only shows one nvme of the inserted few to be active.
I searched this forum for BIOS mods and saw that someone already had done this with a board like mine via experimenting and trying different BIOS combinations.
Unfortunately the files seemed not available and the topic was quite old so I decided to post again trying to find some clarification.

What I learned was that testing and setting the hidden BIOS entries was also possible via GRUB, I saw the approx. layout to IOU IDs on another forum, but messing around and setting hex values got me nowhere.
So I wanted to ask in the forum,:
1. If somebody at best already has a modded BIOS enabling the 16x slots to work as x4x4x4x4?
2. I have read, that higher success rates have been using an ASUS Hyper expansion card, is this true that my cheap ali card could be at fault?
3. Maybe somebody has tested this and knows which IOU IDs map to which physical slots? This could also be handy for testing.

I know that @Lost_N_BIOS did something with this a while ago which was my main point of interest. (Cant post a link to the thread)

Wanted to bump my post a bit, does anybody have BIOS files with bifurcated slots ready?
The earlier threads have the files no longer accessible.
I was testing around with GRUB the soft way, but there seemed to be no impact, maybe I am missing some other settings too.