nope, just wheelie through the tight trees and turn the bars to fit.
Or, in my case, stop, wedge one side through, push forward an inch, swear at the &&**%$ tree, lean the bike to the side, push the other side of the bar through simultaneously ripping flesh from your knuckle, swear at the *&&$$%%## tree again and at the guy who laid the course out, push bike forward another inch, get foot caught between tree and swingarm, back up an inch, release foot, push forward a bit more, stall the bike, dismount(forgetting that the ground drops away on the side you decide to get off on) and fall flat on your kiester while your buddy(who has tears running down his face from laughing so hard) points out the line that runs to the outside of the two tight trees.
Yep.... I run Pro Taper SE's and cut somwhere between the second and third notch on each side. I think each notch might be a 1/4", so I'm taking off a little over 1" total. Main reason I cut them is because I'm a shorty (5'5"), so it's more comfortable for me, plus I think it makes for better cornering for me. If I remember right (too lazy to look up the charts online), all bends of Pro Tapers all come in the same standard width, unlike Renthals and Tags that come in different widths for different bend styles.
For the rocky stuff, where I normally ride, my bars are stock width, 32.5" barkbuster to barkbuster, for more control. When I race in Jersey I have a pair of cut-down mini bars, 29.5" barkbuster to barkbuster, for the miles of endless ignorant-tight stuff.