Doesn't work that way.
Not only are there 10 test strips in a kit. But the small vials that you place the coolant in for the test.
From the Coolant test instructions
If RA is low ( orangish color) add 5 ml of the coolant to the vial with the orange cap, using the syringe to accurately measure the coolant. If the RA us high ( greenish to green) add 5 ml of the coolant to the vial with the clear cap using the syringe to accurately measure the coolant Apparently there is something in the vials that modifies the test based on the RA.
You could buy the extra test strips, but you only have one set of vials in the test kit, So the person selling you the extras would probably keep his vials.
Your best option is to find a buddy with a 6.7L and share a test kit where both of you can use the same vials.