ACROD has an obednitsa service. My dad actually has a copy of the book (he's the church cantor). To my knowledge it hasn't been served in my church which is over 90 years old. As for the service itself, anyone can really serve an obednitsa, although preferably it would be someone who is on the steps to becoming a priest e.g. reader, sub deacon, deacon, etc. We don't use it when the priest is away because my church usually hires a supply priest from the Ukrainian Diocese to do the service when our priest is absent.