The first issue to consider is whether or not you really need a flexibility analysis for your Max/Min temperatures? Theoretically your system will never see these temperatures. However, if you have a requirement to analyze these two temperatures I agree with your cases 1 to 9.

Second, I think your Case 10 is incorrect, it should be L8+L9. I also think it would be cleaner and more obvious if instead you setup L10 = L3 - L4.

Third, you need to evaluate if Case 10 is even possible. Can the system cycle between the max design state and the minimum design state?