It has been a the derech of all Litvishe yeshivas since the beginning in Volozhin to do half a day iyun and half a day bekiyus.
But the question is: What is called iyun and what is called bekiyus? R’ Shach (Orchos Hayeshiva) says that bekiyus is not Chas VeSholom for flying and not understanding; you have a “Chiyuv” to see the Gedolei Achronim such as the Ketzos, R’ Akiva Eiger and the Oir Sameach. On the other hand, he says that one must not do less than 2 Daf a week. I find that very difficult!