Well, if I am right, and in addition to gravity codes, there are both jump launch power and jump height variables independent of their Up-B counterparts, then perhaps it's merely a matter of increasing launch power, decreasing jump/short jump height, and increasing downward gravity, while hopefully leaving Up-B's alone.
Yeah, looks like we might have to find the jump height variable after all, zxeon.
Wait, does the bunny hood affect Up-B's? I'll have to check right now, once my bro stops playing Call of Duty 4 lol.
Edit: Yes, yes it does. Negatively. It looks like both the bunny hood and the metal box increase overall gravity, while simultaneously increasing either jump height or launch power.
In the case of the bunny hood, gravity is increased a bit, and either jump height is increased a lot, or launch power is increased a lot and then some to make up for the extra upwards gravity. In the case of the metal box, gravity is increased a lot, and either jump height is increased a bit, or launch power is increased moderately, again to make up for the heavy gravity and then more to add extra jump height.
It remains to be seen, then, what exactly is causing jumps to be higher. It sure as hell isn't decreased gravity.
Edit 2: I don't know how we're gonna find the culprit here without isolating the variable at work in both the metal box and the bunny hood. The only two things I can think of that can account for higher jump speed would be either a higher jump variable or a higher jump launch power variable, while the two things that can possibly account for "faster" jumps are a higher jump launch power variable or, of course, higher gravity.
As it is, I cannot discern which combination is at work here. There's a chance that there's no such launch power variable, and that what is happening is the higher gravity working in conjunction with higher overall jumps (the ratio, of course, being extremely different between the bunny hood and the metal box). For sure, there is a gravity increase present, as is evident from the nerfed Up-B's. But if it's the other way around, and what is at work is a launch power variable instead of a jump height variable, then how much of the increased jump speed is attributable to increased gravity, and how much to increased launch power? There would have to be enough launch power to overpower the increased gravity so as to make jumps higher than normal, that much is sure.
I suppose a more careful study of the effects of the metal box and the bunny hood could reveal more answers, perhaps by figuring out a ratio of jump height to jump speed. I'm not sure how that would be done, however.