Well here is what I came up with trying them out ...
Works fine when putting 2 digibooks in the sam sleeve for the most part. But I took pics with the big cinedition vs. a premium collection, and then 2 premium collections in one. Pics attached.
In the first two pics, just too much baggage as you can see. In the third pic I showed a side view when inserting two, and its a lot more flush. I don't think this is the best solution, by I know none other. I think regular sleeves would work fine with the skinny digis though.