This all works fine only according to the airports stored in the database. There are plenty of operators around which have a very much tailored database and even some rare destinations are not hard-coded. Very recently an updated database did not show any of the three scheduled alternates as per operational flight plan.
Manual inputs are a daily job as the previous crew had to overwrite your yesterdays data.....
Costsaving is the reply from management, one database for all types of aircraft in operation.