The 6 mil poly acts a capillary break between the EPS (pink, blue or white) – if you insulating your slab – and the ground moisture, right? Therefore does the moisture performance of the insulating product matter that much? Going from exterior to interior, its: ground – gravel – poly – insulation – concrete. Assuming yes, the 6mil poly is present, and in that order, any benefits to upping it, to say a 12mil poly to insure less minor tears and better moisture protection? Maybe even an EPDM membrane? While we’re at it, any benefit to laying it under the footings and overlapping it on the interior side with the slab poly, and on the exterior side sealing it or some other way make it continuous with the outer foundation exterior waterproofing, so in essence, place the house in a “poly sock”, to keep ground moisture from wicking into all exposed concrete, footings, slab, and foundation walls creeping into the home, appearing as effluorescence on the walls and humidity in the basement air. And such as in my case, eventually into the dehumidifier that runs 24/7?