I found a useful glitch a while ago which I call "axe climbing," where you repeatedly jump on a swinging axe to get to higher places. I don't understand how it works, but I do know that it is pretty hard to do, at least without a setup or idea of what exactly you need to do. At the moment, I think using this for skips is only viable in ILs.

In the following video, I show it in action for a big skip in Fling Ring. Note that you can preform the skip using any of the axes, I just used the furthest one because it's closest to a checkpoint.

the same trick can be done later on the level, at the last axe you can axe climb on the ice platforms and save like 3-5 seconds

So, it turns out you can easily climb the axe in Fling Ring by jumping and walking vaguely tangential to it (see youtu.be/JaPN0bFVuvw?t=21). It is extremely lenient, this can 100% be done in a full game run Also: it is way easier to do on the side shown in the video