Custom tools have a different swinging animation, which is not the same as the default one.

Steps to reproduce:
1. Apply a behavior pack with a custom tool that uses format version 1.16.100
2. Equip a custom tool in your main hand
3. Press your button bound to attack/destroy

Expected results:
The animation is exactly the same as it is for vanilla items.
Observed results:
The animation appears to drift off to the left side of the screen more than it should.

Notes:
An addon that also has this issue can be found at https://mcpedl.com/emerald-tools-armor-tools-addon-1/
I have tried this with a pack using format version 1.12.0, and this bug did not occur with that pack.