I have discovered a way to get a maxed out 100 stat and any trait character (immortal included). Achievements and traits are fully enabled with this glitch, and id imagine there is some other insane capabilities with this.

STEPS & GUIDE

1: Start new game, choose any start date and press “Play as any Ruler in __, or create your own!”

2: Pick character, select any county, and press create your own adventurer.

3: Add whatever traits and skills you want or anything else you want your adventurer character to have. This is who you will be playing as after the process is complete. It does not matter if this character’s customization points go over the 400 cap for achievements. Immortal can be added too.

4: save** **adventurer, finalize, submit.

5: Press pick character again and select a random county, create ruler that is under the 400 customization points cap, finalize & submit.

6: Press “Observe” under other options, this will take you into observe mode.

7: Save game, then reload the save

8: once reloaded, press pick character, then press continue without saving, then press whatever button on your platform it shows at the bottom that says “Show Landless Characters”

9: Click on the icon that is over the county you put the adventurer in, select the character then press play.

10: glitch complete, check that achievements are enabled and save the game.

(NOTE: I am not promoting that this is a good idea, just making the process known so that Paradox can eventually patch it to fix the gameplay flow.)