Thinking logically, the BCS has no 'strength' issue, if it gets 'blown open' it bleeds more air from the actuator so so you get MORE boost!
The limitation is the amount it will flow (bleed), although you could get more boost if you hit its limit by fitting a smaller pill.
In Summary, no issue with stock BCS itself, you switch to a 3port to sort actuator* or boost control (rather than level) issues.
Simon
*If the actuator can't keep the wastegate shut against the turbine internal pressure, removing all boost pressure from the capsule helps!