Introducing the Directive Composition API in Angular v15 

Before it is Angular Element, it is a component. Converting components to Angular Elements maps its all inputs and outputs to attributes and events. hostDirectives 'exposes' which is 'adds' inputs and outputs (if needed) so I don't see any problems with that. In the end hostDirectives works the same way as we would inherit from those directives. The change is in the way we implement that which is in this case a composition instead of inheritance which makes is much easier to deal with.