Amazing work. I jut got a wii u that needs Nintendo password to logon but wont create a new user without parental code and there is no forgot pin option to use other methods. Got a Pi Pico at work so tomorrow I will give it a try. Do you have a donation link? - Found it
How long is your Y cable? Had a lot of problems with Y Cables over 30cm and also failures if Drive laid on top of Wii u console (including slow downloads via Nusspli)