Hey ! First of all, i'm sorry but I'm french and 14, so my english is really bad. I founded a skip in the darker side, I don't know if it's faster than doing it legit, I don't even know if it's usefull for the run, but by using the flying thing at the end, you have to take the first tornado for making you go higher, and then shake the joy-cons and by doing that you can go directly to the island with the Bowser painting. I don't have any video to prove it cause I don't know how to record it, but you can all try it, it's really easy to do. Just look out, when you'll be near the island, the flying thing will disappear, and you'll need to dive (ZL + Y, I think you all know how to do it). Maybe it's important so I decided to come here and tell you that, but I'm certainly not the first to discover that.