The latest Airbnb policy makes it per host discretion. In the past, I did not allow them and had two instances when guests showed up without the person who booked, I insisted on that person being there at least at check in, they have called airbnb and both times airbnb cancelled the reservation and gave them full refund even though the person booking had door codes and full access to the house so technically they were just a no show. I was left with nothing as it was too late to rebook another group. I am now reluctantly allowing it but insist on all communication still going through the platform. What is your experience?