I tried this in MMF. Here's what I concluded from a "not be in 1st place" strat:
the item to get for such a technique is star. star has fastest power, lasts almost as long as an orange muhsroom, and still receives the same "faster when powersliding".
But is dropping to 2nd/3rd worth it?
My tests said no.
It is simply too much of a sacrifice to gain a constant speed boost. when you're in 1st and not stopping for anything, you gain a surprising amount of ground. In LR I was vastly ahead of the CPUs, and the ones I encountered had actually all been attacked by other CPUs, which accounted for me lapping them so easily. In other courses where I'm not more than 1 lap ahead of the CPUs, they drive faster, but are still lagging behind me. as I've learned, in gaining distances/killer times, every frame counts.
At the first set of item boxes, I had to wait 5 or more seconds for the CPUs to catch up and get ahead of me. that's a lot of time lost, especially considering that I can shroom at that point, and was almost at the next shroom. by the 2nd item boxes the CPUs were 4 seconds behind me because they had reached their max speed; again, still not worth it.
Stars are fantastic for pulling off some shortcuts (KD lap glitch) and for going through obstacles, but it's best strength, for speed, is in vs. matches or in GP when you are behind. stars can lend to very amazing recoveries from behind. but it wastes time to willingly slow down at the beginning, lose your distance in 1st, just to get a star.
However, I might get star in this run for other purposes. in KD, I'm going to get it to activate a lap glitch, and in KTB it's slightly possible that I can trick the game into thinking I'm in 8th place, and manipulate an item then. and there might be another scenario where I can use it to my advantage. a CPU getting star is actually a godsend to me, especially if a heavyweight and if the conditions are right like in the mega jump just posted.
In the end, with extreme luck I may get it so that one CPU has a very fast start, and it is not as much time lost to drop in 2nd place and get a star, in which case I will consider doing that. but CPUs do seem to have slow starts, and Toad has a very fast start with a boost right at the beginning, and ssMT's/MT's, and usually reaches the item boxes within 3-7 seconds of the start.
I don't think there is any course where I need multiple shrooms to pull off a shortcut. 1 shroom per seems just right.
I'd also like to point out, for those who aren't aware of recent Mario Kart 64 development, that there is a very major shortcut for Kalamari Desert in the works. a shortcut this big/new is particularly interesting, since most of the major shortcuts for all courses that have shortcuts were discovered years ago, so this recent activity is actually very exciting, and I feel very honored to be a major part of it. I'm trying to introduce mupen to the testers as a good means of discovering new shortcuts, using savestates to easily pull off tricky driving, and easily capture an AVI, so it's a nice way of spreading the TASing love, even if not for making frame perfect movies but for test runs/demos.
I also happened to encode a very seductive video from Weatherton, that cleverly uses the blue shell to gain a massive speed boost in the opposite desired direction.
KTB blue shell boost
This is a very sexy boost, and if only the shell had hit Toad on the right side, would've very likely made it to the other side of the mountain.
KTB is very complicated. There's 6 or more shortcuts/glitches that I know of, many untested, many having not even been successfully completed, so there isn't even a route because it's unknown exactly which shortcuts/glitches to use, and in which order/lap to do in sequence.
Figures that the mushroom cup ends up being the trickiest with so many shortcut possibilities and tech.
not as bad as the only item you want appearing on a specific in-game time, but I need to hit the item box and be driving in the exact right way for a mushroom to come fast. what may be perfect could end up in a very long wait for it to scroll through and select a mushroom, at which point I'm already at a steep hill. blarg.
hrm, those are interesting ideas... but again, getting the right circumstances for a mega huge jump like that seem astronomical. if it's the CPU being under star that makes it happen, and not necessarily a boost effect, then it will be even harder. and Weatherotn and I took the 540 theory but couldn't apply it the way we wanted, and maybe this same theory won't be able to be applied the way we wanted but still used regardless.
but phew man, what a breathtaking jump. that has to be worked into this TAS somehow, talk about truly surprising and not expected of this game.