PAA: I’m enjoying your collection of maarei mekomos. Keep them coming!
With regards to how yeshivos learn: In Gateshead as in many large yeshivos two or of three sedorim are bekios. The other iyun seder still has much value even if bochurim could be learning even more bekius. Why?
Most men, after leaving full-time learning do not do iyun. Whether it’s the daf or your own schedule or shiur it’s normally bekius or much closer to bekius than iyun. So if we wouldn’t learn one iyun seder in yeshiva then most of us would never know that geshmak that is a Steipler or Reb Chaim. We would also not learn how to learn a rishon properly.
I do think it’s a fair critique that bochurim don’t cover enough ground in bekius (i.e. those two sedorim), much less allocate proper time for chazuroh. Sugyos properly absorbed as such a relatively young age will remain embedded for life.