BSM is a complete scenes interface replacement for Blender, and the way it works is completely different. As a Blender user, you are going to look at Outliner and Properties panels for any change you want to do (hiding, showing, affecting, etc). In order to change what you want, you need to open the scene/view layer to be affected. That makes Blender to load the entire scene / view layer into memory, and depending on the size of the project, it can take a while. With BSM you don't need to open a scene or view layer in order to change any setting: You have 3 lists: Scenes list, View Layers list and Collections list. When you select in Scene list a scene, the rest of the lists are updated. No memory is loaded at all, and all happens in real time.