Stock BOV, No problems
With Stock turbos you won't have any problems with the stock BOV, except for maybe the dreaded honking goose noise, I am not sure about Aftermarket turbos.
I have been running similar mods for 3000 miles now, including 2 autocrosses. No problems, no honking goose sound.
The problem with the stock BOV is that it can leak air at higher boost pressures. An open element air cleaner seems to cause some stock BOV's to make a honking noise at a certain RPM.
You will not damage your compresser wheels because the stock BOV tends to bleed off pressure at higher boost levels. The stock BOV is adequate to protect turbos. The surge of pressure when you let off the gas suddenly is what harms the turbo. The pressure surge also slows down your spooled up turbo.
The theory behind a aftermarket BOV is to bleed off pressure faster than stock BOV. Less backpressure means less load in turbine wheels. Less backpressure also means that turbos will stay spolled up faster. So you will reduce turbo lag between shifts.
The other reason for an aftermarket BOV is it sounds cooler. You can hear the air purge between shifts, very cool.
There are 2 types of Aftermarket BOVs
1.Vents to intake and 2. Vents to Atmosphere
1. Vents to intake: Greddy Type S and 1G DSM: Takes the extra pressure and vents it between the MAS and the Turbo. The advantage to this is that the MAS measures all the air that passes it and adjusts the amount of fuel needed. If you vent air back into the track the currect air fuel mixture will be maintained.
Because it vents to intake this is fairly quiet
2. Vents to Atmosphere: Blitz SBOV: Takes the extra pressure and vents it Atmosphere. The advantage to this is that it can vent air very quickly and it is nice and loud. The bad thing is the MAS measures all the air that passes it and adjusts the amount of fuel needed. If you vent air into the atmosphere the MAS add fuel to engine for air that was vented. You then will run rich between shifts. This works fine for some people and for other people the car stumbles between shifts. IF you have a VPC (Vien Pressure Controller) you do not have a MAS so the Vents to atmosphere type BOVs work well.