like baragon said, i think this is something that most people go through in their prep. i was def in the same position and made up a study ritual to target lr.
after already going through the lr bible several times, i started again to go through section by section. for example, i'd do the assumption chapter. then, i used the kaplan mastery book & did all the assumption questions there. i also had a packet of prep test questions (some overlapped with kaplan and the lr bible, but there were many more) of each lr question type, which were from earlier tests that i'd already taken & wasn't going to take again. so, i'd do the assumption questions there too. in the mastery book and the packets, i'd do about 10 questions at a time, starting with the easiest then moving to hardest, then i'd go back through the questions thoroughly
to make sure i understood the answers. for the harder questions (in the mastery book they're categorized by difficulty level), i would only do 3-5 at a time before going back through to check.
after i finished one question type, i'd move on to the next. while doing this, i was continuing to take prep tests. if i noticed that i was missing a lot of a certain question type, i would go through the little ritual again for that question type. also, i usually did not do all of the questions in the mastery book for each question type on the first go around, so that i had some new questions to work with when/if i went back a 2nd or 3rd time.
in addition to this study routine, i also think it was really helpful on prep tests to go back and make sure i thoroughly understood every question, even the ones i got right. even though everybody on these boards says to do that, i guess i did not do a great job at first of going back through the tests, so it really helped when i finally did. someone also suggested marking any questions where you guessed, whether you got them wrong or right, wrong. that was helpful to me because it forced me to put more effort into understanding before guessing when i'd narrowed the answer choices down to 2. re: timing, i'd definitely continue to practice untimed, then moved to timing yourself once you see yourself getting more right.
i ended up going from -8 or -9 per lr section to -0 or -1 per lr section. it was like something clicked along the way that made it much easier to identify the wrong answer choices, so that in most cases, there wasn't even a 2nd contender for the correct choice.
Do you think I'll have enough practice (leaving about 10-13 whole exams for the final stretch to June to time them intensively) material left? (I went though the 10 actual, and at the 29th one on the 10 more actual.)
on this, if you purchase pretty much all the tests, you'll be fine. definitely save the most recent until last. otherwise, even if you complete all the other tests, you can go back and do them a 2nd or 3rd time. if you wait long enough (at least a few months while doing several other prep tests) you won't remember most of the questions anyway. your score may be a few raw points higher than the 1st time, solely because you recognize a few questions, but for me anyway, i never recognized more than 5ish max per test.