Hey, sorry for not answering your previous questions more quickly. I wish I had a good answer for my inputs, but I just "feel it out" and don't know any sort of frame data. To gain height on my normal (non-high) flutter, I hold A until approximately the peak of the flutter, then let go of A and hold it again extremely quickly. You might need to wait 2 frames to hold A again rather than 1 frame, but that should be easy to test. I imagine if you go frame by frame and keep an eye on the Y coordinate, you can figure out the best frame of the flutter on which to let go and re-press.
To gain height on high flutter, I tap B at the peak of the flutter. You could possibly gain a little more height by mashing B a few times rather than tapping it.
Same goes for egg jumps, I more or less feel it out. My theory is that you will gain the most height initiating charge and/or throw on the frame during which Yoshi's Y velocity is greatest, but again, you can probably test it by charging the egg on different frames and seeing which one brings Yoshi the highest.
Some potential improvements:
In 3-2, your flutter after melon 24 can be done much faster by gaining height using normal flutters instead of high flutters. See here:
http://youtu.be/YLDAN0cBNAw?t=1m50s
(Note that I use two flutters and then a high flutter, but it's possible with just one flutter and then a high flutter. Also, throwing the egg might save time over cancelling the charge, but I cancel the charge to collect additional eggs.)
edit to above: See the bottom of this post for the fastest method I devised.
Also in 3-2, when jumping down to get melon 3, you can ground pound onto the spring, and the spring behavior will cause the ground pound lag to be cancelled, so that might save some time over a normal jump/fall.
If you can find a place to get an extra egg, you can snipe Power Heart #2 with the egg instead of using your body, which would allow you to avoid slowing down on the leaf.
Hope this helps, keep up the amazing work.
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edit: New content and a couple additional things that might help.
I messed with the spiked ball skip, and this was the fastest method for me:
https://www.youtube.com/watch?v=-c4oTepgdZY
Another neat trick if you don't already know it. If you need to change direction mid-air, then you can flutter for one frame and hit the opposite direction on the stick, which is faster than waiting for Yoshi to slow down and then accelerate into the other direction. Video:
https://www.youtube.com/watch?v=_mORHj-Yl3o
Off the top of my head, white Yoshi could probably save time on: 1-1, 2-2, 3-1, 3-3, 3-4, 4-3, 5-4.
