As soon as you enter the boss room you can pickup guaranteed arrow drops on the left and right of the entrance.
This requires the Goron Mask, stick, and 0th day. With Mayor's Warp, have a bottle over sticks, use SoT, pick up sticks quickly to put them back in your items screen, pause, equip the sticks just before the 0th day effect restores the bottle back on your stick slot again. Once you get bottle over sticks but you have sticks on C, they don't go away when you play song of time and you can still use them. This means we can do goron actionswap to melt Goht's ice with a lit arrow.
By duping a bottle over Ocarina, the game is restored back to a first cycle state. This allows for Tatl text to appear in the Goht room, and in extension allows us to perform Action Swap using it.
By shooting Goht from a certain position and in a certain pattern, we are able to kill Goht without him moving. By delaying the final shot to when Goht begins moving, we can manipulate the blue warp and heart piece to spawn right where we are standing. It is safest to hesitate slightly after sidehopping out twice before sidehopping back twice, as this causes Goht's lightning attack to miss more reliably.
Goht takes 15 arrow shots to die. The video shows a 1+5+9 arrangement, but with good timing, it is possible to fit more than 9 shots in at the end without Goht moving too far, which makes arrangements of 1+4+10 and even 4+11 possible.
By doing a weirdshot immediately after melting Goht, you can kill Goht slightly faster than by doing the traditional strategy. However, saving time with this method is incredibly difficult and not typically recommended for RTA speedruns. You also can use it as a backup if something goes wrong during the fight.
Avoiding having to equip the Hero's Bow over Fire Arrows will save time on its own. To save even more time, you can use a bomb to make Goht fall over, then use Great Fairy Sword jumpslashes for maximum damage output. This is useful for SRM categories that get Great Fairy Sword early, such as in 100% SRM.