Btw, I got it to work while I was in Earth Temple. It triggered when you load data from a file in BiT and then select and cancel a bird statue. Or you could do it many the other ways; like push a the box roll into the tree, open the graveyard, etc. I am not really sure if it would go anywhere, since it doesn't load a new area like in Skykeep. But we did manage to load CS before they happen. So I'll probably work on one of two things. Either find a way to load the thunderhead CS onto files, or start the Early Light Tower CS early.
I don't have a file at that point, so I can't test the skykeep in night BiT. There are so many things that seem to affect what happens and whether it crashes or not. Not sure if it's just the fact that skykeep is open is what's crashing or if there is something else. New files will crash, and the file I had in Earth Temple crashed, but my new 0-char file did not crash.
A clean BiT file will not crash if you have it selected and exit a house during the night. A 100% file that have saved outside of fire sanctuary doesn't seem to crash either (works for both me and kazooie). Anyway, the fact that we're able to load cutscenes before actually unlocking them on a file has been known for a long time (and we both know that), and we can't seem to use them to actually transfer the data over to a file, which sucks... I think it'll only work with cutscenes that have transitions.
Also, I did some testing and I think that I accessed night skyloft during the day, or something. It is messed up anyway.
The file had skykeep unlocked early, it was on a file that had just saved the loftwing. But when I accessed this weird skyloft skykeep wasn't present (but the statue was facing skykeep as if it was unlocked, and the stone was inserted).
There were torches all over skyloft, and they were lighted up, as if it was night.
No NPCs present. There was however a bat outside of the goddess statue entrance.
The bars blocking the goddess statue were spawned.
It basically looks like I am in the Fi Night Escort, but it is day. Kinda messed up.
Edit: after looking around further I'm pretty sure that I'm in the Fi Escort, but it is day. Exactly the same actors are loaded. It is so weird that it is day though.
Edit2: I entered and exited a house. The game now thinks that I've finished the ceremony.
If I try to enter the sky I start to fly around fake skyloft. I can't dismount from the loftwing because I haven't unlocked the ability to do so yet. (what many don't know is that you unlock this & Fi when you insert the first stone tablet)
I also have access to the loftwing training by flying into the loading zone (this is possible until you've inserted the first stone tablet. After inserting the first tablet, the regular loading zones that takes you to the sky appears.)
After accessing the training again the game goes back to thinking that I haven't won the race yet. (and the race will trigger)
Edit3: I managed to unlock light columns early, but it requires files that have already unlocked the tablet pieces.
I noticed some interesting stuff when doing this. If you do not activate the first tablet piece first (and start with the 2nd one for example), when you insert the piece, the game will act as if it was the first piece after the red light column has activated and you'll start the cutscene that takes you to the academy. HOWEVER, the cutscene's bugged. Fi and the fat guy isn't there and the camera get stuck under the ground and it seemed like nothing was happening for like half a minute, after that i decided to skip the cutscene and it properly took me to the save prompt. Everyone wil act as if you're about to leave skyloft, even though you activated the red column.
Only the red column was activated after this since you used the 2nd tablet piece.
I went back there and attempted to insert the 1st piece. The 3rd piece spawned when I tried to insert the 1st one while the 2nd one was already inserted. The green column spawned and no cutscene started after that. The 3rd tablet piece is also gone. Links sound's also muted. You could hear the sword and such, but links voice was gone. (it probably changed to the bokoblin soundset just like it did with the statue wrong warp I found. I could not test the fall damage sound though, so I can't confirm this).
Being able to unlock columns early means that it is possible to skip the skyview and earth temple bosses. And being able to skip the earth temple boss means that we just have to grab the bomb bag and then leave.
We could actually go and get mitts & bombs before skyview temple. I do not think this'd be useful unless we find a trick that requires bombs though, since we have to get slingshot first, or the game will just softlock when you get an item.
And you can't use the Hook Beetle unless you have the regular beetle, which sucks. If the regular beetle wasn't required we could just have skipped skyview temple entirely.
I'll see if I can upload some videos tonight. My brother's currently playing Sc2 on the computer that I use for recording...