Optimizing animated visibility for Unity

Hi guys! I have a character with different cycles which contains animated visibility and I would like to optimize it by removing unused meshes from cycles that does not require them. But unity tends to give a default value of TRUE to the Mesh visibility.

For example, I placed all meshes (Body, L Close hand, L Open hand, R Close hand, R Open hand) only in the Idle Cycle . When I export the run cycle, I then delete the L Close hand and R Close hand meshes as its no needed in this specific cycle. However, when I run these cycles in Unity, Idle works fine but the Run cycle will automatically set the visibility to TRUE when it could not locate the meshes.

Is there any other way to optimize this then? Or a way to inform Unity to set the visibility to 0 if the meshes cannot be found?

Thank you!