I just wanted to understand better the view call in main.hmtl: what is the third parameter {controller_group: 'main'} for in:
{{ view main_path, "title", {controller_group: 'main'} }}
Are there other options or parameters that can be passed to view? Sorry if I've missed something in the docs.
controller_group makes it so multiple view bindings can share the same controller instance. You give it a unique string name between each view binding and it will only load up one. Otherwise each view (title and body for example) would get its own controller.