unit – Replacing bone rotations with OptimizeGameObjects enabled

I'm working with a character model in Unity3D (2017).

OptimizeGameObjects is currently disabled in the character model. Ideally, I can change it for the setting to be enabled. Unfortunately, however, I must control the direction of rotation of various bones (certain bones of the spine, clavicles and arm bones).

I am aware that OptimizeGameObects can be configured to create specified transformations, but these can not be modified directly to affect the rig. Is there a job here?