Another possible alternative to "too fast?" I call it "Fixing Too Fast by Going Faster." This uses Tott.
1. What if you ignore all of the restrictions we place on ourselves and just go as fast as possible? Do the route normally up to Master Sword, except don't wait for FH night time (you should if you didn't pop into BPR first try; this might actually be a waste of time overall though, not sure how long Song of Passing transitions are)
2. Superswim to Northern Fairy, sail to FF2 (an alternative to this would be to use sva's route??)
3. Up to Ice Ring as normal, using faster strat to get in, perhaps superswimming from there to Earth Temple (this is hard and you apparently can't drown by it to pop up on it, though you apparently can once you've beaten Earth Temple for whatever reason)
4. Superswim to Wind Temple, doing things as normally up to the end of it
5. Superswim to Overlook, getting the 200 rupee chest if needed
6. Superswim to Stonewatcher as per usual
7. At Stonewatcher, climb up a ledge in front of one of the palm trees to WW dive and get dry storage. Superswim into Islet of Steel. This is easily performed by first superswimming right up next to the guard ship, then charging another superswim to go right past him
8. Everything after this is normal up to the Ghost Ship farming, where you warp to Windfall and obtain the Song of Passing, since it shouldn't even be close to night time if you've done this quickly enough.
This is, of course, assuming the time saved by superswimming is worth obtaining the Song of Passing, and while I assume it is, you'd need to perform pretty well for this all to work. I haven't timed anything yet, but seeing that I've actually lost around 3 minutes due to it not yet being night time when it comes time to farm the Ghost Ship (using current route), it really does seem like this could be faster.