If I put a hold on a quote, but an instant booking is requested at the same time, I'm wondering what the priority will be when the booking request hits MyVR.
This is Channel dependent. Some channels ask us to record a booking. For these channels, such as HomeAway and Airbnb, MyVR can respond that the property is unavailable if we notice a hold on a quote. Other channels, such as Booking.com, tell us to record a booking. In this case, MyVR responds by creating the booking and warning you in the reservation detail page that the reservation overlaps with a blocking calendar event.
When a calendar change is made, is the update pushing to all listing sites, or does it wait until the next scheduled update?
We do both. We attempt to push out updates as soon as they happen, and we also do periodic updates to ensure that nothing falls through the cracks. This includes updates to listing data as well as availability data. The frequency and speed of syncing, however, are channel specific. It is possible to have a booking that doesn't immediately update on TripAdvisor, for example.