Since the sim topics are unknown for any given exam, it's not really possible to target the exact content. Sims are just more in-depth assessments of knowledge. I think the best approach is to make sure you understand the material thoroughly. Journal entries, calculations, and tax forms, etc., are all important areas on which to focus some extra effort. That way, you'll be prepared as you can given that you have no idea which topics may show up.
If you know you're weak in certain content areas, dig a little deeper, and work a little harder preparing in those areas. At least if you have more than a shaky understanding of most topic areas, you should be able to work through the sims at an average level. This is what makes the CPA exam so challenging – the breadth of content that is fair game.
I don't think there are any shortcuts around a real command of the subject matter. BUT . . . one can certainly study in more efficient/effective ways. Think outside the box on that, in terms of a more dynamic approach. A combination of techniques involving multiple senses can really make a big difference – auditory, visual, and hands-on. Research has shown that learning can be accelerated with the involvement of multiple learning styles, senses, etc. Think about mind mapping, mnemonics, or even a little jingle you could use to more quickly store and recall information as you study. I definitely think this is an area all of the review programs can capitalize on even more.
Anyway, I'm rambling now. But, my main point, in answer to your question, is that I would not do anything differently in preparation for the sims being weighted more heavily, except to focus on gaining more than a superficial understanding of the content areas. The sims Becker (or any other company) provides are not necessarily representative of the actual content that could appear on any candidate's actual exam. They serve as useful examples of the ways in which exam content may be tested in a simulation.
FAR - 94 (7/10)
AUD - 99 (8/20)
REG - 99 (10/15)
BEC - 88 (11/20)