Just on the off chance somebody cares:
BOV next to intake manifold is very responsive, will snap open straight away when you back off.
BOV right next to turbo will be very loud, but wont be as responsive. There might be a small delay between backing off the throttle and the BOV opening.
BOV somewhere in between eg on the intercooler gives you a mix of the two
And congrats on the mint silvia
very tidy.