Difficulty 3 will set game difficulty to PotD. I don't know if it will limit you to one save or not, but it does increase combat difficulty. You can even increase it more (to 4 or 10 for example), but I don't know the point at which combat will become impossible.
I haven't figured out the scaling command yet, but I'll keep trying.
Hmmm interesting. What do you mean by limiting me to one save or not? Do we know if it causes any other bugs/issues?
I'm sorry, that was just me being an idiot. I was thinking about the Trial of Iron and somehow mushed that into PotD. I don't know about bugs/issues, I didn't play around with it for an extended period of time. I did try difficulty level 10 and I couldn't cause damage to enemies then, but I was also experimenting with a save from very early in the game.