From the little I have found on the subject, piston to valve clearance is an issue as overlap increases. I have also found information that Hemi's need less overlap due to the ports flowing straight on from one to another.
What I have not found much of is dyno testing on Gen 3 Hemi engines where camshaft swaps are done to test LSA. Frankly many of the test I have come across are not using what I would really call aggressive cams. Perhaps due to the engines being EFI and not needed, supercharged applications, or simply lack of variety of grinds. I realize I will be in a minority with my build of naturally aspirated with carbs, or possibly carb style EFI.