I have no idea why, but my SteamVR completely reset all its settings. Along with it, my boundary came back, and I cant remember how I got rid of it years ago.
I thought it was as simple as doint standing-only calibration, but now thats just making a blue circle.
I just want it completely gone, no black square, no grid, no glowing circle, and I didnt have any extra 3rd party tool to do it before.