Orbitize! is a Python package that streamlines the process of modeling the orbits of directly-imaged planets. The orbitize! development team aims to make planet-fitting faster and more accessible by combining multiple existing techniques into one code base. The VLTI-GRAVITY instrument has demonstrated that interferometry can achieve 10x better astrometric precision than existing methods, a level of precision that makes detection of planet-planet interactions possible. I have replaced the standard Keplerian orbit solver in orbitize! with a module using REBOUND, an N-body solver, in order to account for planet-planet interactions present in the data. Users have the option to use this module when modeling highly precise astrometric data. I will present this updated implementation in orbitize!, discuss validation tests I performed, and discuss future use cases.