I'm used to seeing a 3-port VSV, with an in/out for the main pathway, and a 3rd port to actuate the switch. Do you have 3 ported vacuum ports on the sniper, or is the brake booster connected to the intake manifold? On your VSV, can you show a pic or do you have any documentation on it?
Take my advice w a grain of salt, Im more used to the carbs: But the ported vacuum as I understand it (typically on the base of the carb) will pull a vacuum strong enough to actuate the VSV when revs are higher in the range as opposed to idle, whereas the vacuum on the intake manifold will do the opposite. The idea is to desorb the canister when the vehicle is in a healthy operating range rather than potentially throwing off the air/fuel mixture during idle.
Im not familiar with the sniper, but I would think that most modern ECUs would want to time the release of charcoal fuel vapors after the engine is warmed and only during certain RPM bands. You might consider an electrically-controlled switch for the vacuum port. Im not sure what folks recommend as far as dumping it out into the air cleaner or the intake manifold (mine does the latter, but again, carb).
routed the hoses.