The 40s are very misleading: LG and RCs are a lot easier and LRs tend to use the same tricks over and over. The 50s and 60s should be fine though but I think LGs in the 80s are more time consuming (morebrute-forcing your way through) if not harder.
Ive always erred on splitting no matter what. And I think if you cant figure out any inferences within 20-30 seconds just bruteforce. But as long as you can keep making inferences i think its valid
... tunnel vision and try to bruteforce and answer every question in ... my process. I specifically use bruteforce as a last resort, after ... boards from other games before brute forcing as well.