What users out there are using their stock plastic bpv in. 08+ wrx and what kind of stage 2 pressures are you running without issues on the bpv? I am not talking about what kind of pressure you heard/read might work or fail, rather what are you tuned to and hitting without plastic bpv issues?
The bpv isn't about breaking at high boost like the tmic, its about leaking from opening prematurely. You won't know it and can't do anything about it. Physically though what's going on is the Ecu is trying to target say 19 psi. With the leaking boost the turbo will have to push more boost to reach its target. So the Ecu and boost gauge will see 19psi but your turbo will be pushing 22-23-24psi. A log will be able to tell because flowing that hot of air can cause knock and WGDC will be outta wack. Either way it's a bad thing and stressing the turbo out.