Which Lightning Web Component custom event property settings enable the event to bubble up the containment hierarchy and cross the Shadow DOM boundary?

While `bubbles: true` allows the event to bubble up the regular DOM, `composed: false` prevents it from crossing the Shadow DOM boundary, meaning it will not propagate out of the shadow root where it originated.

For a custom event in a Lightning Web Component to propagate up through both the regular DOM tree (bubbling) and across shadow DOM boundaries (composed), both the `bubbles` and `composed` properties must be explicitly set to `true` when dispatching the event.

With `bubbles: false`, the event will not propagate up the DOM hierarchy at all, and `composed: false` also prevents it from crossing the Shadow DOM boundary.

While `composed: true` allows the event to cross the Shadow DOM boundary, `bubbles: false` means the event will not bubble up the DOM hierarchy once it crosses the boundary, limiting its propagation.