Switching est setup whilst on the mountain-

The Custom V-Rocker is a really good board, and rides switch pretty well, despite the fact that it's directional.  The setback is only 10mm, which won't make that much of a difference in the park riding switch.  The best idea is to use the ease of adjustment you get with ests to find a stance width and binding angle that you're comfortable riding with, and then learn to ride switch.  The most difficult thing about switch is overcoming your bodies desire to rotate back to its most comfortable position.  Just take your time, focus on good form and you'll do great.  And don't wait 14 years to learn switch like I'm doing.  The better you get riding regular, the less you'll want to get good at riding switch, since you're basically starting over again.

With that particular board I wouldn't worr yabout it.  The Custom has something like 1/4" set-back, might as well be centered.  Most people have more angle on their front foot anyway, which effective makes you centered.  Being close to centered makes switch riding a little easier, but that's so little set-back I wouldn't even worry about it.  

Don't trip out over stance too much, just find something that works for you and stick with it.  Unless something just feels absolutely wrong, just stick with it.  I also wouldn't worry too much about set-back unless you're talking about a pow day.  

If you still want to switch it up, go ahead, but I wouldn't worry about it too much.