It was pointed out in youtube comments of the published run that there's a second possible fight skip on the second half of the Red Ribbon Army level. You simply go under the bridge just like the first one. The real kicker is that it's super easy to do (even in real time). Skipping the fight causes a major change to RNG and allows for a much faster starting pattern for the boss. In total there's about 6.5 seconds of improvement.
Managed to improve it by a few more frames by not dropping down to the ledge with the extra life.