I'm all for harder content if the reward is there.
I would soon hope into a dungeon and have 2 paths, easy patch with 2x trash, or boss with harder less forgiving mechanic.
Then the party could chose which way to go.

To 1st boss normal
Let's people in DF know what party can do.
Then it would be a door all 4 members interact with the door pick easy or hard path, if tie random, if wipe hard path closed.