I'd probably question the way you approach un-timed sections though. You shouldn't treat them as "extended" timed sections. Lingering in not good timed or un-timed. You should be 200% sure that the answer is right AND 200% sure the other 4 answers are wrong. You should have reasons for each (why the answer is wrong and why the answer is right). In un-timed work you should, especially early on, write down these reasons. I normally do shorthand (if an answer is Weakening a Strengthen question I'll write W and then underline the word(s) that weaken it.) You should never guess in un-timed work. If you honestly cannot figure out the answer and you do guess in un-timed work its the same as having a wrong answer. Not having the same reasons for an answer being right/wrong (as compared to your study material) is, in most cases, the same as having a wrong answer. That means even if you answered correctly you may not have answered efficiently and may have to re-evaluate that particular question. Be methodical and efficient - even in un-timed work.
If you work like this early on then it will take you a long time to get through questions (which is why it is un-timed). The whole point of un-timed is so you can get so accustomed and familiar with this type of rigorous scrutiny that it becomes second nature. Your time will then naturally come down. By the time you really master un-timed work you should already have a pretty good time. The only new skills you should practice by the time you get to timed practice are question/game/passage ordering, bubbling techniques and section management.
Hopefully that helps?