Sorry for the long writeup but there's a reason I'm trying to write my thought process / order of operations ;)
I considered the possibility of reducing vertical jumps, to save that 1 frame they incur. I think that's only really possible on Level 1 and 4, where you have freedom to do any path you choose. Level 1 and 4 contain zero wait frames, and never retread on a square twice, so they are done in the minimum number of moves already. Since your spawn square has to be bounced back to, I'm not sure there's a way to step on every square only once using less than 10 up/down movements, which is what this run does. So that seems great.
I made a Lua script that marks the 12/13 frames after an input as lag. This helped immensely in finding the spots where there was an input delay for manipulation/survival.
https://pastebin.com/ipUXAYzr
I found 23 such spots, a lot of which being waiting for the eater's first move in the 10 stages of Level 2 and 5.
From the looks of it, the eater does not actually have any luck involved? It seems to me more like he chases you in a logical way that will always be consistent if your position and his are the same. Also, his time to start moving seems fixed, so the starts in Levels 2 and 5 probably don't have anywhere to improve.
Any delays to manipulate his movement after he wakes up could possibly be shorter, if done earlier in the level. But I was more interested in any delays that were due to the Pin, because THAT is definitely RNG.
Once a level starts, I'm guessing the sequence of the columns it spawns in is fixed, unless the Pin is interrupted (like by hitting the eater). But, you can delay exiting a previous level to change what columns the Pin is in the next level. Probably a simple frame-timer RNG, not affected by the player's input, if I had to guess.
Going with what wasn't going to desync anything first, I noticed a Pin delay in the final level, 6-5, and removed it, then delayed the last jump of 6-4 by one frame. This did successfully make the Pin miss me, and luckily the Eater cooperated. I saved 5 frames!
Not being too afraid of the idea of resyncing, I restarted from the first pin delay in 2-2, delaying my 2-1 exit just 1 frame to eliminate the 2-2 delay. That ran into a bit of trouble in 2-3, but in the process of trying to fix it, accidentally discovered a far far faster idea: Manipulating the Pin to be in the rightmost column in Levels 2 and 5, to kill the Eater before he wakes up!
When waiting at the end of a level, every 2 frames you wait moves the Pin's starting column leftward once, which is nice since it means a maximum of only 12 or so frames to wait. This can potentially be reduced if you can manage to spawn the Pin an extra time during the level (by manipulating the Eater to die). I did this in 2-4, in order to resync 2-5 faster than I could have by waiting.
I have to go to bed right now but I'm currently 148 frames ahead starting Level 3. Frame 5769 is where I stopped. Will work on the rest tomorrow and I encourage you to check it out as well! Pin manipulation to kill the Eater has potential to reduce other Eater waits too I'd bet!
http://tasvideos.org/userfiles/info/64114279732085918
