Hello fellow GOGers,
I am interested in buying the "Divinity: Original Sin" games, and I'm looking for the most complete bundle that grants all goodies from the entire series, but the different game editions are a little confusing to me. I already have the original Divinity anthology and their respective goodies.

Are there any goodies that are only available in either the D:OS1 Enhanced Edition Collector's Edition or D:OS2 Eternal Edition?
I'm particularly asking in regard to the "Divinity 2 Digital Soundtrack (previously unreleased material)" that's being advertised in the D:OS2 Eternal Edition? Is the previously unreleased material already contained in Divinity 2?

Which combination of game editions grants the complete games + all Goodies:
D:OS2 - Eternal Edition
D:OS1 - Enhanced Edition Collector's Edition + D:OS2 Divine Edition
D:OS1 - Enhanced Edition + D:OS2 Divine Edition

Is the D:OS2 Divine Edition equal to the Definitive Edition + Divine Ascension Upgrade?

The reason I'm asking being that I merely want to buy D:OS2 right now, but retain the option to buy the entire rest later.

Thank you in advance for your answers.