This movie unlocks Time Attack starting from a clean state. Delete the 3DS/User folder if this doesn't sync for you! For whatever reason, running this movie a second time desyncs due to some lag frames being different the second time around. Here's an encode of this TAS for your viewing pleasure.
TASed using Bizhawk 2.10 on the US version of the game. The ROM I used is the trimmed and decrypted .3ds ROM that I dumped myself from the physical cartridge that I own, so if you used a different method of obtaining the game then your hash might not match mine.