PCLK is 48MHz +/- 2% accuracy for CY7C65211/215.
Although the KBA you mentioned is not considered the PCLK error, the best way is to include this error for the accurate calculation.
Anyway, to meet the margin within +/-5% is not difficult even if you consider the PCLK error.
I agree with you.
PCLK has +/- 2% accuracy.