I also assume that incomplete phi-features on a DP match with incomplete phi-features on T. The incomplete phi-features could be interpreted as incompleteness or absence of phi-features.
due to the absence of agreement on T, caki with incomplete features, rather than Chulswu with full phi-features can check its own Case features and the EPP features on T. the Agree operation applies to caki and the lower T. Chulswu with unchecked features must move to Spec vP to obtain an external theta role and then moves to Spec TP to check its nominative Case and the EPP and phi-features of T. Another assumption is needed to obviate the distance crossing over the CP 1.