I think what you're referring to as "temporary fill strips" are actually the strips used to create a recessed coaming. They're laid at 90 degrees to the centerline of the deck in an oversize opening (mainly longer at the front and rear). The cockpit cut-out is made in these strips and the coaming is added. The end result is a coaming that's flush, or nearly flush with the the deck at the front and rear, yet still provides ample clearance for installation of a spray skirt.