For a 525 to 705+ jump, I would be careful about assuming that your foundation is already fully solid. At 525, there are almost certainly still meaningful gaps in knowledge, skills, strategy, or execution across Quant, Verbal, DI, or some combination of the three.
A jump from 525 to 705+ is absolutely possible, but I would not approach it primarily by doing more mock tests or working through the Official Guide.
At 525, you likely still need significant development in your underlying GMAT knowledge, skills, strategies, and execution.
The first thing I would do is look carefully at your section scores and identify where the biggest weaknesses are. Then work systematically through those areas topic by topic.
For example, in Quant, you want to be sure that you can reliably handle the major tested concepts rather than simply recognize the formulas. In Verbal, you need strong Critical Reasoning and Reading Comprehension processes that you can reproduce under pressure. In DI, you need both the underlying Quant and reasoning skills plus specific proficiency with Data Sufficiency, Two-Part Analysis, Tables, Graphs, and Multi-Source Reasoning.
I would strongly recommend using a comprehensive GMAT course for that stage of your preparation rather than trying to build everything from Official Guide questions.
The Official Guide is useful, but the number of questions available within many individual topics is limited, and it is not designed to provide a complete learning path. If you have a weakness in a particular area, you may need dozens of targeted questions plus detailed instruction before that weakness is truly fixed.
I also would not start taking a large number of official mocks yet. Practice exams are primarily assessment tools. They tell you what score your current skills produce. They do not efficiently build all of the skills required to move from 525 to 705+.
So, I would recommend this sequence:
First, build your knowledge and skills comprehensively, topic by topic.
Second, do extensive targeted practice until your accuracy is consistently strong.
Third, begin adding timed mixed practice and work on pacing and execution.
Finally, use fresh official practice exams to determine whether your preparation is translating into your target score.
At this point, I would spend far more time learning and improving than testing yourself.
If you post your Quant, Verbal, and DI scores from the 525 mock, I can give you a much more specific idea of where I would start.
Good luck!
Scott
Target Test Prep