Not too long ago we switched internet providers to T-Mobile Home Internet and the speed has been a huge improvement, but recently a problem has risen to my attention of the NAT type on my family's Nintendo Switches being fairly restrictive for playing with other people.
Unfortunately while I have been assured by their service that it is getting worked on being added, currently they lack required options for port forwarding or opening the correct ports to help with it. I know the Access Point would have its own internal options which would probably include the options I would require, but I don't know if it would still run into the Gateway's system and the options would amount to nothing.
Unfortunately the options would amount to nothing so long as the T-Mobile device is acting as your router. The port forwards you wanted to set would still be unable to traverse the T-Mobile device to reach your access point or home router. You might check with T-Mobile if they have the option of setting their device into Bridged mode; that would basically bring raw internet onto the network ports on their device, and a home router with the port forwarding options you need could then be attached. Bear in mind that if they do that, you would be completely responsible for the access point / home router setup.