Obviously there is more than just the flywheel that differentiate the v6 from the V8. Just because the V8 car doesn't do this, doesn't automatically implicate the DM flywheel. You'd be best served asking this question of V6 owners with the automatic trans, because they will have a flexplate, not the DM flywheel. That may give a clearer idea of causation.
2014 Premium GT, SGM, Brembo, Auto, Tech, Comfort, etc. GT500s, Steeda UCA, VMP auto N/A tune. 100 shot nitrous on BBR tune. Best e/t 11.42 at 120.64
2012 Premium GT, Candy Red, Brembo package, 3.73, MT82, Comfort, Tech, et al. Procal tune, Roush UCA, UMI poly LCA, GT500s, Steeda red bracket, Hoosier 28x10x16 bias drags. Best e/t 11.91 at 115.23 RIP