During my attempts at figuring out how to get faster bosses than what I had been getting, it was brought to my attention that utilizing a hard reset will set up your boss fights to have predictable patterns. As long as you move Left or Right at the same times during the fights, you'll get a predictable pattern, but it was also discovered that pausing the game can change the patterns you get somehow.

During my 24:14 session, I experimented more in depth with trying to get ideal fast boss patterns but I couldn't get the VZR-5 fight double drills at first. Tomkabs mentioned about the hard reset, so I did that, redoing all my save-states along the way with a hard reset pattern, but my menu/save/load button combinations all require start and select. This led me to a slightly different Bandal fight and a much slower VZR-5 fight. Tomkabs asked if I was pausing to set up my save states, and I went back through it one more time, making sure every save state was done when it is impossible to pause. This resulted in the same pattern start to VZR-5 as tomkabs and BeetZero, and I had earlier discovered how to change some of the boss patterns by moving left or right, or mixing it up.

As it stands, I need to drill in my movement pattern for Bandal yet, as this fight is the longest one that can lead to time loss if you move the wrong direction once the boss's attack disappears. He can usually re-appear fairly quickly, but I had a pattern I worked on that I just didn't get a chance to have it sink in yet.

Between tomkabs and myself, we found a simpler solution to stage 2's Anrock boss. Tomkabs talks to G-13 twice, then Locke, then G-13 2 more times. This results in only needing to shoot the boss's attack twice then you're at 100%. I found that you can keep talking to G-13 to gain 5% until you cannot use talk anymore to bring the total to 85% which is 1 attack shot and you're at 100%. If you mis-menu, you won't get enough from G-13 to get the reduction, so it's best to just get the 2 additional after Locke and go for 2 hits. This results in around the same time cost for either method.

I experimented Talking with the other bosses, but I didn't find anything like Anrock.

I want to add this info here. Did some more experimenting. Found a ~2s faster pattern for Zalta, but then I started "choking" my setup for Bandal. Turns out that it wasn't the start press that changes the patterns on bosses. It was what direction you killed the boss(es) prior. We kill Bemel going left, Anrock hasn't mattered if it's left or right (left if I get my menu 1 foot kill, right for the 2 foot kill), Zalta everyone has killed going left, Bandal going left and this gives VZR-5 the double drill pattern going left. My faster kill on Zalta I killed going right, but it made Bandal 3-4s slower than what I could do and it gave a full left movement pattern. I experimented and killed Bandal moving RIGHT, and that did a non-drill VZR-5 fight.

Some day, hopefully soon, I'll get the run in with all the little improvements on the bosses I've found, as well as all the movement (except the frame-perfect platforming jump in Act 3, not worth losing 2s if you miss for .5 gain).

One more finding to note, it does not matter if you use a hard or soft reset to start the run. The boss cycles are determined by the direction and cycle you finish the prior boss in (cycles are a little more forgiving though).