Changing your right click key to spacebar allows you to throw items/use items really, really fast.

So I changed my right-click key to the space-bar so I can auto-fish easily. I used XisumaVoid's design which has an item frame used in it. I somehow started spinning the item frame at a million miles per hour. I realized that when you change your right-click to space-bar and use an item (door, snowball, fishing rod, etc.) it will start to speed up incredibly. If you move, it'll stop doing it so fast. If you press F5, it'll stop as well. Here's a short video of it: https://youtu.be/2u9_b6v1IDw

Edit: Just found out it doesn't have to be spacebar, it can be any key. I've also confirmed it with a few others, and they say the same thing happens with them.