Currently using Choices in a WebComponent results in issues with some events, most notably the "click" event due to retargeting in events that bubble out of the shadow dom. It has been pointed out in this issue:
#805

Keyboard events however work as expected, since the event listeners are not being added to the documentElement, but instead they are added to this.containerOuter.element, so the event.target doesn't get "retargeted" by the time the event is captured. Is there a reason to give different treament to these events types?

In a simple test on my WebComponent where I have a simple single select input everything seemed to work as expected when adding all listeners to this.containerOuter.element.