I don't follow.
I have done the N249 bypass, I have unplugged both piece of vacuum hosing (from inlet manifold to N249 & from N249 to DV nipple) and connected them together with an inline hose joiner. This means that the N249 is now doing nothing and the throttle is in control of the vacuum needed to open the DV so why do the x2 nipple on the N249 need to be blocked up if it's not doing anything? What issues is it going to cause, I have none currently and it's been this way for 6mths?