I am a fan of single-sided swingarms, but is the juice worth the squeeze?
The VFR swingarm is quite a bit longer than the stock swingarm. This will obviously affect handling, assuming that you can properly dial in a shock to provide proper suspension travel for the weight of the bike and rider. Your bike will now require more effort to turn. In addition, I highly suspect that the VFR swingarm is heavier than the stock CB swingarm. IF the swingarm is heavier than its stock counterpart, are you going to improve the power of the engine to compensate? Even so, the bike will have more inertia and require additional effort to change direction.
If the purpose of the bike is to drag or just for looks, most of the foregoing can be ignored -- except for figuring out how to dial in the suspension to that the rear properly hooks up on acceleration.
Just curious. Maybe you've already taken off of this into account.