I am following this thread keenly coz I am ready to start assembling my H9 CAP-232.
A friend of mine bought the Sig Extra 300XS and replaced all the CA hinges with robart hinges.
While I don't know about 1/4 scale planes and how the stress affects the CA hinges, I can comment on smaller planes.
I had (past tense

) a 40 size Kyosho CAP 232 which I used and abused for 2 years. After about an year, the CA hinges started to fail one-by-one. First the aileron's, then the elevator and then rudder. They would split right in the middle as if they were being cut.
That makes me wonder if CA hinges just have a typical life span ?