We could modify the component to match the suggestion made in the ticket's description:

selecting the top most match for the user.

This would then imply replacing the selection behavior of the Lookup to make it automatic instead of manual. Borrowing from the design patterns described by the W3C in the WAI-ARIA Authoring Practices for a similar component (combobox)...:

List autocomplete with automatic selection: When the popup is triggered, it presents suggested values that complete or logically correspond to the characters typed in the textbox, and the first suggestion is automatically highlighted as selected. The automatically selected suggestion becomes the value of the textbox when the combobox loses focus unless the user chooses a different suggestion or changes the character string in the textbox.

To complement this behavior, validation should be displayed when the entered text doesn't match any of the options (i.e. there's no matching suggestion, so the automatic selection cannot be made).

Hey Sarai, thank you for your suggestions. I think they're great and we should implement those changes to the components if that still makes sense in your opinion.