I think you're spending too much time analysing your built-in natural skills and not enough time focused on simply improving process.
The key to reaching your GMAT target faster is to equally focus on conceptual knowledge and test taking skills. After you've mastered all the core concepts in quant, then as you practice you should spend time diagnosing your process gaps.
For example, are you capturing all the information and then pre processing it to maximising the information available to you as you start calculating? The same goes for visualisation so you're not caught up in the wordiness of some problems.
Specific diagnostics and targeted practice questions are the key -- ones that are focused on your exact gaps. You could make it easier on yourself by enlisting the help of a GMAT performance coach.