We report new tests of the linear dependence of the p‐value of aftershock sequences on the magnitude Mm of the triggering event for the Taiwan earthquake catalog. This effort is motivated by the quest to validate this exclusive prediction of the multifractal stress activation (MSA) model. This model assumes that the seismicity rate depends exponentially on the far‐field applied stress and on fluctuations due to stress transfer from past events. We use three different declustering techniques and carefully analyze both the long‐term and short‐term time‐dependent magnitude completeness of the Taiwan catalog. Using stacked aftershock sequences in different ranges of triggering mainshock magnitude Mm, we evidence an empirical linear relationship p(Mm)≃(0.11±0.01)×Mm+(0.38±0.02), compatible with the one previously observed on various other catalogs. The coefficients of the p(Mm) linear dependence from catalog to catalog do not appear to significantly correlate with any tectonic or structural feature.