For now, the C: drive from the Win 10 Pro machine (very similar setup) will just stay in it. Luckily, I have a couple new spare SSD’s hanging around: One of those is the drive for which I’m asking about the allocation in the Win 11 Pro machine. The data drive in the new machine is the data drive from the Win 10 Pro machine — I just physically swapped it into the new Win 11 Pro machine. Works like a charm...
Oh, I see, it was already just a data storage drive when it was on 10 so the 11 sees it fine.
Found some information for you: