Evil_3D, in this instance, it is better to point out how the capsule animals can be improved rather than identifying a sequence of inputs that make it faster. This is caused by a few reasons. The capsule animals will stay in sync once every 32 frames and with improvements coming before this point (hitting the capsule earlier, more pausing before the boss fight to save in-game time, CPZ), the animals may have different timing to jump.
Hitting the ARZ2 capsule as is, there is a timer that will allow animals to spawn until it expires, then the game checks for animals on screen. In this case, the timer is at byte 00FFB59F. Ideally, this would count down by 1 unit per frame from 179 to 1, then change to 180 for 1 frame (this is when the check for animals occurs), and then change to 0 (indicates all animals are off camera)[all values given are Unsigned]. In the file provided, the timer stays at 180 for several frames because a flicky is late leaving the left side of the camera. Without changing anything before the capsule hit, the fastest way is likely achieved by deleting 1 animal spawn, in this case it is the animal that spawns at the 40 bytes starting at 00FFB8C0.
This post in the Sonic 2 thread by marzojr describes deleting and adding boss explosions and animals, along with a Lua script, which contains a lot of information
http://tasvideos.org/forum/viewtopic.php?p=423921#423921
Alternatively, the animals that will be loaded can be manipulated prior to hitting the capsule. In most levels, this is done by deleting or adding boss explosions but there are none in this level. However, destroying badniks also manipulates the animals and there is an opportunity to so during the time spent waiting for an air bubble (this would require redoing some of the level).
