I've wondered about the rigidity myself. The idea behind free-floating is that the barrel is allowed to resonate and flex freely so it is unaffected by any slight changes in fixture as well as disruption of resonance. So, I would expect poi to shift if it were touched. Harmonically balancing the hammer and reg will do nothing but help accuracy. I do a lot of experimenting with different wight pellets, different designs, and different diameters. Each gun has a sweet spot depending on the barrel and power setting. Balancing the valve and reg will reduce turbulence, boosting stability