Since uploading the last video, I've learned that Forsaken City can actually be completed without pressing left at all, as well as 3 more leftless berries there and the heart in Old Site. Watching a 100% minimum grabs video makes me think at least half of my left presses in 4A can be avoided. Because making a video with just these improvements would be a bit short (and I'm too bad at video games to pull some of them off), I'll post a compilation of everything I miss at the end of the series.
I've also learned that I'm not the only one trying this challenge on KZfaq. Old Site leftless was mentioned in a Reddit post about a year ago. I suppose I'll just go until completing 8A since I'm attempting maximum berries as well.
0:00 Start
2:50 Seeded Berry (didn't practice)
7:50 Shrine
12:46 Old Trail
15:49 Cliff Face