fArGo fArGo, This is a nice idea and I've used that methodology before. A pin/password of grapheneos would be 4727436367. However, I have "Scramble PIN input layout" enabled. That would cause a migraine entering a pin/password LOL.
SgtSurehand has the solution. It will give you a full keyboard to enter your upper lower case numerical pin/password.
Hope that works for you. And the GOS devs wouldn't need to change anything.