Hi bebe,
Unfortunatelly, you won't be able to accomplish that with EntityReferenceBase.Load in a coroutine.
Is there any particular reason you are using EntityReferenceBase.Load instead of EntityRelationQuery?
You'll be able to complete the same task using EntityRelationQuery with the plus of being able to use it in a coroutine.
For instance:
...
var regionERQuery = new EntityRelationQuery(territory, EntityRelations.FK_Territory_Region.ToRole2Link);
var regionQuery = regionERQuery
.With(myQueryStrategy)
.ExecuteAsync();
yield return regionQuery;
...
Regards,
sbelini.