A configurable mod the lets you keep full speed while using items (Eating, blocking, drinking, etc)
By default this mod turns off the slowdown effect on the following items:
Any item can be added via the configuration menu ingame or by editing the config file manually.
Why do I speed up when using X item:
You don't that's a visual effect caused by the zoom in effect on that item. If you feel like you experience this with an item that doesn't zoom in, let me know
Does this work with X item:
Yes, as long as you add it to the config file
X food/shield/bow/potion/thing from mod y isn't working!
It's likely the mod doesn't have their item setup the same way as vanilla (descending from the base class of the item).
You will have to either ask the mod author or put the item into the config file youself.