Yes, I've seen a planned layout which I think had another Star of David runway pattern north of the initial runway pattern. Quite why they thought they needed all of those runways is completely beyond me.
Are you thinking of the 9-runway plan (the Star of David south of the A4, plus 3 in a triangle to the north) ?
I've never seen a plan for 12 runways, that really would be OTT. What's your source, if you don't mind me asking ?