This post is over a year old but I am still having guests that cannot find check-in instructions.
This results in guests not being able to get in for hours if I am out of reach, or if they arrive in the middle of the night and I cannot hear knocking or phone notifications. Making it unreliable defeats the purpose of having it at all.
This is probably one of the most important features of the app, as travelers cannot use a computer on the street and may not even have internet access when first arriving in the country. They need to be able to find and download it from their phone at the airport.
The fact that so many guests are not able to find such important information is a huge problem that needs attention. I searched myself for help from airbnb to relay instructions to my confused guest (as a host I can't see what they see), but all I found was this. That's a problem.