Tvheadend

I'm setting up Freesat in the UK.
What's the difference between the "Over-the-air: UK: Freesat" and the "Over-the-air: UK: Freesat (EIT)" Grabber modules?

Surely both use EIT? Which do I pick. And do I need to use the "uk" scraper configuration for one or both of these?

Finally, is it correct that I won't be able to see the Freesat channel bouquets unless I enable one of these?