The Q82-84 is a magical point on the GMAT or sometimes just one or two questions may result into the score.
There’s a certain human element which may cause you to score higher or lower. But specifically this band between 82 and 84 is quite accurate based on my analysis.
Hopefully I am wrong and you score Q 90 but I wouldn’t count on just that alone.
In part, going over 90th percentile on any section, requires a huge discipline with careless mistakes, timing, and being able to give up when need to.
I would recommend checking questions that have eaten a lot of your time to see the solutions - a lot of times there may be multiple solutions some of which are much faster.
Another aspect to consider is that for some topics you may be better off doing a quiz with a bunch of the same questions versus a test that has a mix so there is a certain weakness you’re seeing or sensing in the back of just do a number of questions in a row for that topic until you can get a pretty high accuracy. I would say hundred percent accuracy with exception of a careless mistake sometime in which you can address later