I set up a scheduled message to send to the guest at the time of booking, and it's delivered before the automated Yale message, allowing me to regulate our guests' first impression. At the end of the booking email, I include, "You will receive an automated message from our smart lock provider shortly." This helps mitigate the confusion of the Yale message. I haven't received a single complaint about it yet, but, like everyone else on this thread, I would really love to be able to customize the Yale message. It's very clumsy and confusing, especially the part about virtual keys.
"Virtual keys offer better security and easier access. However, if you are not interested in virtual keys or you do not have a compatible smartphone, please contact your Airbnb Host to make alternative arrangements to access the property."