Sadly the engine doesn't allow me to freely change the animation for the floor damage effect. I can only change the colors and visibility, but when I make it invisible, there is no effect whatsoever to indicate to players that they're taking damage.
I assume the repeated flashing on the screen would still cause the same problems, even if it's less visible, right?
Fast Learner is supposed to be the last resort, when people don't need any more skills anywhere else, not a cheat to quickly level up.