I am currently trying to learn the English route for TTYD any%. I was able to get goombella buffer pretty easily, but bookcase jump has been really difficult for me. It just feels really random to me, even after watching ed's tutorial on youtube. I have gotten it 4 times in about three weeks of about an hour or two a day of practicing it. Normally after the spin jump I land right near the corner of the bookcase, but I can never get on top. Is the spin jump frame perfect or is there some way to get the timing down with a metronome like runners have done for uhe / yoshi skip?

Bookcase Jump can usually be tricky for those learning. A metronome is not remotely useful for a trick like this as you cannot time the spin jump with a metronome. You need to spin jump at the top height of Mario's jump. You can not simply just quickly tap the A button to get the right height since it will give off a short jump, you need to make sure you get a full jump with your spin jump. The timing will become progressively natural over time.