I generally agree that it makes sense that the MS can in fact act as a tuner. However, all these groups that have been posted are not definitive proof that this is happening.
I can see differences between with and without the MS but what is missing is the wrap around i.e. without, with, and without, with. So what would be reasonably convincing (remember this is still and n=2 for each condition) is to show that the groups done without is identical, and with is identical, and they are different from each other. Without this, one could say that what we have are two different groups and as all of us know, even shooting the same ammo out of the same gun at the same target sometimes gives us different looking groups.