Gonna bump this now, there were some interesting posts in the SDA thread. Although no one actually said they're planning a run, user groobo posted some neat sequence breaks, notably in order to
get to the veil early and
bypass the tentacle blocking the body, which allows you to skip Beast form and Li / Sunken City entirely, apparently. The Veil trick strikes me as particularly clever, the Body shortcut is more like "wow that's so obvious that I guess no one tried it". In any case sequence breaking is half of what makes these things fun.
groobo goes on to outline the optimal route as energy -> nature -> sun -> dual, which is probably correct. Sun and Nature are probably interchangeable unless there's a viable briarhopping shortcut somewhere.
[Edit]
Oh, and I might have found a shortcut of my own! I was playing around and discovered that it is possible to get into the Sun Temple from the east side. What you have to do is jump up to the area where the Roc is. Normally jumping off to the left wouldn't give you enough momentum to reach the ledge where the Sun Temple is, but if you use Nature form and plant a briar under your feet, it'll shoot you with a much higher initial velocity than you'd normally have, and if you angle it correctly you can reach the ledge above the Sun Temple's east side... from here it should be a simple matter of briarhopping up the glass tube leading to the memory, and then either dropping down into the temple or possibly continuing left into the boss chamber shortcut.
Only downside is that it probably requires beastform to get up to the roc's area to begin with, and it doesn't save enough time to justify going to Mithrala if that can be skipped entirely. Maybe you could use a trick similar to the one used to bypass the current leading into the Veil, but I kinda doubt it.
At the least, the briar superjump could probably be used in order to climb up the left side of the sun temple quickly, although launching yourself at the right angle seems pretty difficult.
