Vaultfan, you've done your homework. Good job!
vaultfan wrote:The tip of the pole should not be allowed to simply fall freely directly into the box where it will bounce (possibly back out of the box).
In my experience, the pole has never bounced out of the box. This is probably becuz I aim for the back of the box rather than the middle. As soon as the pole hits, my weight is already on it, so there's no chance to bounce out. This does take perfect timing though.
Just a few more comments - mostly about what wasn't discussed re pole drop ...
I agree that the pole should be held at an angle where it always appears near-weightless. Rather than talk about angles (which mean nothing when you're halfway down the runway), you can 'feel' the right angle, which varies as you gain speed down the runway. If you find that you're holding the pole up (resisting with the lower arm) then the angle is too low. If you find that you have to press the lower arm (which is actually higher than the top hand during most of the run) forwards, then the angle is too high. Use your lower arm to balance the pole at the exact angle that makes it feel weightless. The angle will vary depending on the direction and speed of the wind, too.
You didn't mention anything about the rotation of the pole from the side of the runway. Some vaulters feel more comfortable carrying the pole slightly sideways. However, my preference is to always carry it perfectly aligned with the runway. This is to avoid the need to apply any sideways pressure during the last part of the run to align it into the box. Remember that any pressure in any direction causes an equal and opposite reaction to the rest of your body. This usually translates into slowing down in the critical part of the run. Even the slightest pressure and the slightest subsequent slowdown makes a very significant (negative) difference in take-off speed. And take-off speed is the only part of your runway speed that matters. The rest is just foreplay.
Next, I'd like to point out the problem with dropping the pole too early. Too late is rather obvious - a late plant has serious consequences that I need not elaborate on here - that's a whole other topic! Too early, and you'll be applying upwards pressure with your lower arm on the pole (and downwards pressure with your top hand), in an effort to keep the pole from dropping on the runway before the tip gets into the box. As per the previous point, this upwards pressure will cause you to lean back and slow down. Once again, you need to SPEED UP on take-off, not slow down - even if it's ever so slightly. If you time the pole drop properly, you'll be leaning forward in preparation for take-off with a good forwards angle at full speed.
One last point about whether or not you can actually accelerate your forward lean into the take-off by causing the pole to drop quickly - however you worded that. This sounds good in theory, but in practice, you must think about how you initiate an accelerated 'drop' (to be faster than gravity). Unfortunately, the only way you can initiate it is by pressing the pole forwards/downwards. Due to Newton's 3rd law, that's going to cause a slight leanback/slowdown during the part of your run when it's most important to be leaning forward and accelerating. So despite the theory, IMHO it's a bad practice.
In summary, I think the best you can do is make your pole feel weightless, as you and I both described.