I have a GReddy, it sounds awesome, it is a bypass valve, looks like a blow off valve.
If I ever get a FMIC, it can be made into a blow off valve by removing the reciprocator pipe and screwing the trumpet back into the port.
Plugging the gas return to the turbo will just create agony.
You need to read this whole thread, honestly. It will slowly show you why.
There has been endless trial and error with this. Until you have a post TB MAF, you are going to run rich, stall, go into limp-mode, other torment...
The many brands with convertible valves leaves you to know only what you know now, and be safe with a good upgrade. Until you are running over 24psi, there is no use, though, the stock piece is good to 24psi. After that it is a valve issue.