Here is my use case: I am designing a sound absorbing partial box. It started out with a left side, front and right side. There is a metal frame, wood sides, covering of sound absorbing material and plastic edging around the open sides and corners—wherever the sound absorbing tiles may be cut.
I organized the bodies into folders: Frame, Wood, Absorber, Plastic. Then I need to make a change to the design. Now it has left, right, front and top. I wanted to focus on the plastic parts in the lower portion of the project. I put the top plastic parts into a sub folder that is nested in the plastics folder.
I hide that nested folder, then I back out to the top level and select the plastic folder. Only the bodies I want to work with are highlighted. So far, so good. Now I click the isolate button, and to my surprise, the hidden parts are now revealed along with the parts I wanted to isolate.
What I was expecting was to have only the non-hidden parts isolated.
It was easy enough to get my desired result without using isolate. However the behavior of the isolate button was not something I would predict.
My feature request is that the isolate function should not show hidden bodies.