It's difficult to make a worthwhile TAS of a rhythm game, but this challenge is fairly well-suited for a TAS! The scoring system behind the DS game has always been shrouded in myths and misconceptions, so it's interesting to see exactly how the game can be contorted when one knows exactly how it works.
From my understanding you didn't need to do any "early/late"s, but you also chose to go for the lowest possible score, right? Was it to save time? This way there are no scoring comments at the end of each stage, and Superbs are bad because they create Perfect opportunities later on which slow down the menuing. Or did you just do it for entertainment? I gotta say it's downright hilarious seeing stuff like Crop Stomp being accepted with 0 crops collected. Or is there a technical reason with the scoring that I didn't catch? This is something I feel should be elaborated in the submission details.
What is the purpose of the RNG manipulation? I only ever knew this game as being random in one spot, which is the order of the ditties in Big Rock Finish. Is the "invulnerability period" you get after a miss random?
Achieving the bare minimum rating in each minigame is purely for entertainment purposes. Calculating the minimum # of taps is still the top priority. I didn't even realize about the Perfect Champaign feature until halfway through development.
The RNG in Big Rock Finish does not need to be manipulated, since it only determines the order of each section. What does need to be manipulated is the "invulnerability period", or "cooldown" as I would call it. The cooldown always starts with a set # depending on the leniency of the minigame. However, the subtrahend is RNG dependent for every frame. This basically means that by manipulating this RNG (by pausing and unpausing the minigame), the cooldown can last longer by about two frames; which, under the right circumstances, can save an extra tap.