So now that we're adding new hats again...

[GlitchR]

A hitbox visualization would just make things less frustrating. There's nothing about this suggestion that would make PR2's most brutal maps any easier maps, considering the execution needed is still their most prevalent challenge.
If this hitbox visualization was just a toggle, you could still play them just like they've always been.

Hitbox vizualization just making things less frustating is not true. Estimating the distance between you and the desired target and then pressing according key strokes in order to execute the move have always been the most prevalent skill in the game. The hitbox will make this a lot easier.

Hitbox can be utilixed to help you in multiple ways. Prime example is movement control. Space between your charachter and and hitbox can be used as metric to determine how much you're able to move said direction. Which is very useful when you need good control. Not to mention the straight outliners of your hitbox which help a lot too. All of this makes the execution a lot easier. There's more to this and will be more if this update will come to pass as people will discover more ways to take advantage of it. 

Also you bring up the point of the most brutal maps. Hardest trap levels are one of them and I can see hitbox having largest impact on them. Although its evident using hitbox makes effect on other hard levels as well. Saying this because I suspect you have not much experience in these type of levels.

If hitbox becomes a thing there's never a reason not to use it any gameplay in pr2. So turning it off puts anyone in needless disadvantage. My explanation of taking using hitbox to your advantage is not through as in my original post (something went wrong when trying to post) But I'm open to elaborate more.