You lost me a bit with your OP.
We know eVent is a WPB, not just a DWR. The specs seem to vary though from manufacturer to manufacturer. That's clear from looking at the articles just on this site.
But not sure what you mean by 'DWR Silnylon.'
You did mention the MLD bivy made of Pertex 10 denier Endurance.
Don't believe that is a silnylon in the sense that silnylon usually refers to nylon with a waterproof silicone coating on both sides. Good qaulity sils run at least 3000mm HH. Pertex claims Endurance, on the other hand, has a HH of 1000mm. http://pertex.com/fabrics/endurance/
That is not sufficient to be relied upon for waterproofness like that provided by the better silnylons, or to meet requirements for military use.
1.1 oz nylon is also readily obtainable form many suppliers like OWF and Quest with a light silicone coating that makes it DWR, but not waterproof, and probably less than 1000mm HH.
So I interpreted your post to be looking for breathability specs for nylon with a silicone based DWR treatment; specifically, like the better ones such as Endurance.
I would like to know that too, especially for selecting a windshirt fabric, for example.
I think Richard may have tested some of the DWR 1.1 oz nylons in his epic posts.
But most of those were for HH, not breathability as I recall.
Still, that might be a good place to look first.