Turbo engines usually have a low static CR and run up to significantly higher boost levels. They can and should use higher boost triggers as a result. 8-10 psi on a static CR of around 8.5 is usually where detonation just becomes a concern.
SC engines, especially those with higher static CR, will hit detonation at much lower boost levels. Triggering at boost onset or at very low boost is necessary and appropriate. If you are not experiencing any bogging your boost trigger setting and it is pulling hard through the range you are likely in good shape.
And yes relying solely on WI to cool the charge (no IC) also reduces the desired trigger point.
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