It's showing up for me just fine. I don't think the Divine Ascension DLC has anything to do with the Divinity Engine 2, it's just digital extras after all. There's a couple of check boxes for me on the main DOS 2 page when I click on it from the library, one being the modding dlc one.
The Divinity Engine 2 is under tools as well, but I think you've got that installed already by the look of things.
Last edited by Ghatt; 15/09/17 10:37 PM.