Yeah that's what I was thinking... I would hope the AP tune plays well with the EBC considering the guy who tuned the car does MS3's regularly and tunes the GReddy EBC's all day anyway. I'll get in touch with him to see what the map boost targets are set at, I don't know how it works with the AP map if he was tuning the EBC and not using the set boost targets from the ECU.
I know it's definitely installed correctly, reinstalled the valve unit monday to a better location using reinforced hoses, made sure to follow the instructions to the letter again and I have it sourced directly to the stock BPV source from the intake mani for the best response. The BOV is now getting its signal from the brake booster line, installed a vacuum manifold in line with it for a few extra vacuum ports. Checked everything for leaks multiple times and haven't had any issues after the install there.
I'd have maybe thought that using the brake booster line is giving me the issue with the BOV but it was doing this before when I had the EBC and BOV tee'd to the same source, so my only guess is that it IS the EBC.
In which case from my other thread you were correct and I do apologize if I sounded patronizing at all with my reply.
Damn these smart ECU's not liking extra toys.