User blog comment:Hayashi H/Advanced Equipment Guide/@comment-749631-20151112020535

Just put 4*bombers on carriers anyway, as proficient planes also give acc bonus and some very early stage test found the accuracy might reach 100% with the help of aorcraft proficiency under certain condition [THIS IS NOT PROVEN YET.] Also, it's basically confirmed that more proficient plane also mean more proficiency bonus and these bonus are post-cap.