Perhaps let players configure some number such that the game will never plot a path for your character longer than that without first getting your confirmation.
"The path you've chosen is longer than N steps, are you sure?"
And then I also feel this needs to be very easily toggleable. Like a persistent UI button. I'd have it on when exploring and off when backtracking, and those two activities are back and forth all game.
Relevant screenshot below. The entire level is explored, and this damn piece of grass sent my character haywire then I trapped at the X. This kind of thing has happened to me on much later levels and messed me up good.
In the Depths, I would set this number to something like 2 for safety. I can't count how many times a misstap has gotten me zapped, chased, and then pincer-attacked by some second enemy in the room behind me. But then I'd want to toggle it off to run back to an alchemy pot or whatever.
Yeah, I agree about the arrow. I wrote about it in a different comment.