i think the bov needs to be the closest to the throttle body and the maf sensor before that
therefore, the air being released has the quickest escape with minimal backflow,
air ----B(^)V-TB-> insead of air ----B(^)V---MAF----TB--->
if you have your maf sensor between your tb and bov then the air between will be going back and forth (over an air-flow sensor!!)between the charge-release
---B(^)V---(<-->)MAF(<-->)----TB--->
maf sensor before the bov means air will always be moving in one direction (whilst passing MAF)
---->MAF ->---B(^)V-(<->)-TB-->
my 2cent