If you don't add that many schedules during testing you always can import the first export file and you will have most if not all schedules imported. Aside this only series schedules are important as one time only recordings are only set for a very short period of time and could be redone in the new TV engine imho. But series (recurring) recordings can be existing also there is no actual program to record. Those are much more "critical"... If you're adding new series recordings they most likely are existent in current EPG so you easily can add probably missing ones after the import...I expect to have to do the migration several times during my testing.
For series that are not currently being broadcast, it is possible to create the xml definition of the series, and then import just that single definition into "TV Server". The definition is added to the existing schedule for the other programmes.But series (recurring) recordings can be ... no actual program to record.