Safe to run without Evap VSV plugged in?

Hello! I'm hoping if someone can answer a quick question for me. My 04 Prius is idling roughly, and I'm wondering if I've got a bad purge valve. Specifically, it's the EVAP VSV that's easy to access, just to the left of the ICE. I don't have a pump to test the valve, so I was hoping to just unplug the electrical connection to put the valve in a fixed state, and see if the idling behavior changes. I read somewhere that this could result in a pressure buildup in the Evap system that could be harmful. Is this a real risk? I'm pretty mechanically minded but I'm not familiar with this system. Thanks!


For mor information, I started having misfires and rough idling a while ago, and have so far replaced the plugs and the coils, which it was a good time to do anyways (130k), and neither solved the issue. I recently bought one of those BlueDriver things, and it's telling me that the EVAP 0.020" and EVAP 0.040", as well as the "Purge Flow Monitor", so I thought this valve would be a good place to continue diagnostics before going on to something more challenging/expensive.