Increasing Vne structurally

[Tandem46]

With all the talk of Vne lately, I'm genuinely curious how does one increase the Vne of an RV structurally? Does one simply build a tail with thicker skins? I ask because when Van's came out with the RV-7, he increased the Vne from the RV-6's 200mph to 230mph (200kts). This quote is from the Van's site at the time of the RV-7 release:

Can I use my RV-6/6A empennage kit on an RV-7/7A?
Maybe.
Because of the higher Vne, the RV-7/7A MUST HAVE the thicker 0.020" thick elevator and rudder skins AND a counterbalanced rudder. The thinner 0.016" thick skins that are standard on the RV-6/6A, and the older RV-6/6A rudder without the counterbalance, are NOT FOR USE ON THE RV-7/7A.

Is it that simple? If it is, one thing that confuses me is that the above says you need the thicker elevator and rudders skins, but my RV-7 rudder skins are paper thin. I don't have the thickness numbers on me, but the original RV-7 rudder skin was a one piece skin much like the elevator skins and of similar, if not exactly, the same thickness. When Van's enlarged the -7 rudder to counter undesirable spin recovery characteristics, the new one was a two-piece and very thin. Yet the Vne didn't change? The rudder horn was much larger. Did that compensate for the thinner skins?