So if you have a modified setup which is SC -> TB. Where is the ABV if its still fitted?

If the ABV still acts as a bypass around the SC it would flow enough to prevent any damage to the SC or anything else. The BOV might keep things a touch cooler & a touch cheaper on fuel by flowing more thus lowering the pressure ratio spike on gear changes?

3mm might not seem much, but X the Circ = a reasonable area...

Thanx for the help with the oil too Brett