I'm wondering how to handle many map layouts in QGIS that have different symbology? As I am making layouts and trying to make them jive together (different scales, showing different things) I feel it is incredibly inefficient to set a layout, change the symbology for a different layout, and then when I go back to the previous layout to change something, I have to change the symbology back to what it was? How can I manage this better?
What you are looking for is called Map Themes with this you are able to register the state of each layer (visibility, style used) and give a name to the configuration. Then in layout you may set each map to follow a specific theme.
For this to work effectively you will need to create several style your layer (read this to get started)
Closely related : QGIS: Map theme with layer visibility AND style, does it exist?