Leaky BPV or hose collapsing?

[evidence]

I've had a Prosport elec boost gauge on my ride for maybe 6 months now tapped off the BPV line, and up until 2 months ago it was reading perfect. Recently at anything above ~10PSI it reads 1/2PSI low compared to my Dashhawk. The air filter has always been in place, and the sender unit has even been tested by Prosport as reading correctly. I figured maybe the cheap hoses that came with the gauge weren't able to hold up, so I picked up some nice thick silicone vacuum hoses from boostcontroller.com and swapped it all out, every contact zip tied nice and tight. Still reading low.

I know it's been said the brake booster line is better to tap, but something recently changed as the BPV line _was_ reading great. It started reading low before the AP, but with that I'm running more boost now with the AP, so it'd be odd if that line was not reading full? Sound like a leaky BPV?

[evidence]

Noone has seem similar? Everyone saying their stocker is leaking, is it just conjecture or are you seeing eratic boost?

Side question.. I know on many engines AFRs in the 12s make the best power, has it been shown where we make peak?