Considering how the scaling in the base game works I don't think a Black Desert type of approach to health bars and knowledge of monsters would work very well. A good idea, by all means, and I'd love it as a mod if UI would at some point become accessible for modding. But by how the game is laid out I think that would turn out to be more of a negative effect on the average player than positive. (Due to the often large difference a level or two can make to the difficulty of a battle).
For GM however, I can understand the wish to hide levels from the player for some particular instanced reason. A checkbox to hide level in tooltip could be cool, but I figure changing the entire backend stat system and health bar UI just for GM mode would be too much of an ask.
Again, knowing less about the enemies and going in blind has tons of fun potential as an idea. Maybe core attributes and UI will be more accessible to modders in DOS3 / Engine 3, who knows 😏😊
