What are the bare-minimum port-forwarding requirements for NAT Type Open on Xbox One?
The Portforwarding website is a tried and true source for this information. According to the linked page, the following ports need to be opened:
TCP
- 53, 80, 3074
UDP
- 53, 88, 500, 3074, 3544, 4500
Just remember to assign a static IP address to your Xbox One, and then assign those opened ports to that address per your router's settings. I don't see anything there about skipping certain ports, but I imagine that trial and error of closing certain ones until your NAT becomes restricted again could give you the answer you're looking for.