You are correct. However, a level 40 creature also has resistance to bludgeoning, piercing, and slashing damage at +5 and below. Thus, they take half damage in general. I realized early on that even with the boost I was giving them with my epic table, they don't have enough HP. This was a clunky fix. The 2nd drafts will resolve this problem.
Interesting to know, I look forward to the second draft.
Since characters will be not leveling past 20 and will instead gain quintessence, will you eventually have a chart for what amount of quintessence equals a certain "level"? For example, your character needs to have "20 quintessence" to be considered level 30; ergo being high enough level to fight a CR 30 monster.