Oh nice, I see what you mean by the inventory menu! I think directional buttons there would be great and simplify things!
Also, like Ganimoth mentioned, they did get the password input working by using a txt file, but that does require decompiling the game, updating it, and recompiling it, so I'd rather not go that route.
With the R36S, do know that they do not have built in WIFI, so in order to play you would need a usbc wifi dongle. I am using a RG35XX + which is slightly more than the R36S but does give you wifi/bluetooth.
Let me know when you have the new build and I can test the update with the port to make sure it works well with it.