@b0id
Welcome to the Win-RAID Forum!
As you can read at the bottom of your first post, I have moved this thread into the better matching “BIOS Modding Requests” Forum section and customized the title of it. If you want, you can change it at any time by editing your start post.
Now to your request:
I seriously doubt, that it will be possible to implement the requested support of a 2TB NVMe SSD by a BIOS modification done by the user.
On the other hand it may work even without such risky procedure:
According to >these< product specifications of your Lenovo laptop >1TB sized M.2 NVMe SSDs may be natively supported.
The failure to get the new SSD (other manufacturer/model and size) working by simply cloning the complete data of the old SSD is not a proof, that the new SSD will not be usable at all with your Lenovo laptop. What your new SSD may need is a new boot sector (EFI boot partition) with the correct information about your new SSD.
My advice:
Try to get Win11 clean installed onto the new SSD. If you don’t know how to do it, please read the chapter “B. Best/safest procedure to get Win10/11 properly installed onto an NVMe SSD”, which I have layed down within “Step 4” of >this< Guide.
If the clean OS installation should by successful, you can decide at any time to replace the data of the drive C: by the previously cloned old drive C: data (don’t touch the new EFI partition!).
Good luck!
Dieter (alias Fernando)