Sorry, I'm just now seeing this, with the way Snowtop Village is being tested for skips and glitches we will need 40b for Thyra like you were saying. We have been close to skipping the water shrine and other cut scenes in that area. You should definitely check out the discord for what is currently being theorized for routing, if you haven't yet. There is also a speed flow chart in the works that will show the progression of how to beat the game with glitches as known for now. It will have links to all the glitches and optimizations we use and be updated with current theorized paths that will skip certain parts.

Updated route for forest shrine skip. Saves ~0:06 in movement from FFG to MR

In this video I showcase what to look for when finding ways to get out of bounds with Ash. Hopefully this leads to a better understanding of how to get out of bounds in the game and leads to new discoveries and skips for the speedrun.

This is a demonstration on how to enter Thorns Pass early. At the moment there is no way to progress further than the first area.

This is a demonstration on how to skip the forest shrine. This saves around 1 minute over all. Info for the skip in video description.