@Shock_Tart sorry for the late reply, I just saw this.

The purpose of hitting the box with the vine is to force enough sprites on screen so that when I go down the 4-2 pipe, there isn't a pirahna coming out.

To make the 4-2 glitch work, I'm doing several backward jumps into objects throughout 4-2 (3 jumps). These jumps move mario's position on the screen forward. The pipe and vine locations are close enough that, upon going down the pipe after these 3 backward jumps, it sends me to the vine location. I'm not 100% sure how it works to be honest... It is very similar to the -1 world glitch though.

One thought about what you said though.

Since I am legitimate, even if you may not believe that I am, I am curious about the limits of human perception (visually/bodily). It has come to a point where, I'm not timing the walljump, I just KNOW when to press it. That is to say, my muscles know.

I think I have an extraordinary gift in muscle memory.