This patch removes some of the jankiness with releasing items during spin jumps. Normally the direction you face during a spin jump (and thus the direction an item is thrown) depends on the level timer and switches every 4 frames. To mitigate this, my patch does two things:
1. If you drop or up-throw a shell during a spinjump or a capespin, it will be released from mario's center. This is similar to how it works in Super Mario Maker and removes the pseudo-randomness coming from where you are in your spinjump.
2. Direction held on the d-pad (i.e left or right) takes priority over the direction that mario faces. This lets you kick items while you spin and be able to know which direction they are going.