Maybe I'm misunderstanding but wouldn't you use the "If (api.Cons.IsLocalCurrencyForEntity() And Not api.Entity.HasChildren()) Then" beginning to narrow down all base entities then have your calculate line as normal?
Something along those lines might be possible if you could "push" the data from the source entities to the destination entity. However, I don't believe you can write data outside the Data Unit currently being processed. As such, you have to "pull" the data from the source entities to the destination entity. The other problem with "pushing" the data is that you would have to come up with a way of aggregating the data in the destination entity, whereas "pulling" makes it easy to reliably aggregate the data.
Apologies - I read it wrong. I didn't see that it was adding together multiple base entities into one entity. Ignore my comment 🙂
