Power Inspector contains two different modes for how component unfolding is handled in the inspector.
You can unfold any number of components without restrictions.
The unfolded states of components are remembered when you return to targets.
This is how the default inspector always works.
Only one component can be unfolded at any given time. When you unfold any component, all other components on the GameObject drawer are simultaneously unfolded.
When you select a component, it will automatically be unfolded.
Unfolded states of components are not remembered when you return to targets. Instead all components always start out unfolded.
You can temporarily bypass this restriction by holding down control when you unfold a component.
This can be a useful mode when working with GameObjects that contain many components. It avoids having all components after the couple first ones being located outside the visible portion of the inspector view when you select a new target.