The PTS standards only outline the bare minimum needed to recieve your ratings. The factories are using their own DPEs and you'll usually see pretty much the same checkride every time (before you get your panties in a wad, most examiners use the same basic checkride every time). The only thing you will accomplish in 90 days is learning the bare minimum required. It's the only thing you really have time to do.

In the mean time, you're missing out on valuable lessons on weather and other important topics that you shouldn't be trying to learn while sitting in the right seat teaching somebody else, or while doing .78 with 50 people behind you.

There are so many valuable things you can learn by taking your time and looking around a little. Dive in a little deeper and you'll be a better pilot for the rest of your career as a result. Rated and proficient are two different ballgames friends.