Rocks(ACOC user) was negged by Imu, the SHP and the other people at Gv are objectively being protected from DR by plot unless Oda gives us some new information about it. There's no reason to assume Imu can't DR Zoro and leave, Imcel just doesn't think it's worth his time.
So yes, Imcel can neg diff ACOC users, we saw him do it on panel.