Found a small sequence break involving a bit of jumpery around the Fish Hatchery. Takes about two minutes to get to the western entrance to Sequoia from there with no fights.

As you can see, I got in to the 5 crystal checkpoint without having 5 crystals. Could be a 0 crystal trip, but I didn't want to make a new file just yet.

I can confirm this works with 0 crystals: I'd made a similar trip before based on a casual player's input. Thank you for documenting it! I've added a link to this thread to our tricks guide so people can find it that way if they look for it in the future.