Compressor Surge Line?

Has anyone played with the compressor surge line table under Airflow > Turbocharger?

I have a 1.0 EcoBoost Fiesta and installed a Turbosmart BOV a while ago. I was getting a lot of compressor surge with it connected the way the instructions said, so I wanted to try to connect it to the factory vacuum line to see if it would help. It's much better now, but it's still not perfect. It works perfectly under heavy load, but still gets some surge under medium load and a lot of surge under light load. Sometimes it also will begin to vent, then start surging, then vent again.

I have the valve adjusted as soft as it will go to try to avoid surging as well.

Is there something specific that I can log to try to sort this out? Has anyone dealt with anything similar?

Thank in advance

As a reference, here is my stock table

Edit: Had the wrong description. Updated image.

I have left it connected to the factory vacuum line and it's been okay. I have the blow off valve pretty loose to avoid compressor surge, and if you go anywhere above 50% throttle it behaves as it should.