I have an object with mirror and multires unapplied, and I want to bake it with higher details while maintaining optimization, but I get the message noted in the title of this post.

Here are my configurations:

[![enter image description here](https://i.stack.imgur.com/hMdhg.png)](https://i.stack.imgur.com/hMdhg.png)
[![enter image description here](https://i.stack.imgur.com/O3aG4.png)](https://i.stack.imgur.com/O3aG4.png)