Would note that, as this mod applies to me, I'm too old and fat to appreciate the ability to do wheelies and no longer have a need to "lift" my front tire over a log or large rock in my path. Dead possums, snakes and raccoons tend to "give" when the front tire encounters them.
I don't think I've ever gotten into the left lane to pass a vehicle on the Interstate while on my KLR, even one piloted by an 85-year-old sporting Sansabelt slacks and massive, wraparound sunglasses, much less a vehicle on a two-lane road.
Probably the reason I seem so lackadaisical about the .22 mod is that I don't see it improving my riding experience to any degree. In fact, for the way I ride, almost exclusively gravel roads, if anything "improved throttle response" would be a hindrance.
When I'm riding these roads, I'm usually over-geared, treating the throttle with kid gloves to keep the drive inputs to the rear wheel at a minimum: just enough to keep me moving. On some roads I can get up to 70, but most of the time it's 40-50, keeping loose, concentrating on the horizon and trying to ignore the feeling in my feet, hands, brain and butt that I'm going to go down at any minute. The KLR has never taken me down on a gravel road, even fresh, loose, 6" deep gravel beds. When I'm in this mode of riding, the last thing I want is a "snappier" throttle. The sedate, stock KLR throttle suits me just fine and probably keeps me out of a lot of trouble.
So, while I still believe the performance enhancement of the .22 mod is maybe minimal at best, it's just something I don't need or want even if it works. It just seems on all the forums that the .22 Mod is touted as a "must-do" mod for everybody and that your machine is somehow lacking if you haven't done it; something to brag about around the campfire or in your signature line, if you will.
When I think about it, it seems like all my farkles are "anti-performance," adding nothing but weight and drag for the sake of comfort.