Not being able to jump past an obstacle or through a gap because your player is clipping the edge by literally 1 pixel is super annoying!
Nintendo fixed this by implementing what I call "Soft Edges"
It means that if you player is jumping, and clips the edge of an object by a certain threshold, the player will slide around the edge and continue the jump. I've included a .gif to demonstrate this.
It's a major quality-of-life improvement for platformers, especially those with a predominantly vertical orientation or tight spaces. It could be implemented by adding a single parameter containing the threshold (0 = disabled).