I’ve used it thrice! Worked each time and was more convenient than waiting on hold. There were several minute delays between each message though - not unexpected as you’re directly in touch with the specific property. Used to cancel a reservation after normal cancellation cut-off date/time. Used to request early check-in. Used to inform about a glass I broke in a bathroom (why put actual glass items in bathrooms?!)

Kinda glad it’s an app feature. If something is urgent, calling is always an option.