Huhu =)
When using latest Version of Brutal Bosses in1.16.5 (V. 4.7 on Forge 36.2.42)

latest (6).log

the log throws a mixin error. The pack still loads and everything, and I'm not sure how critical this is, but I wanted to let you know.

The config references BasePressurePlateBlockMixin, but the class file is not present in your JAR.
Mixin tries to load it, can’t find it, and throws:

The specified mixin 'com.brutalbosses.mixin.BasePressurePlateBlockMixin' was not found

Cheers