Predicted initial positions that simulate the observed heavy element masses and the corresponding predicted C/O ratios for the five simulated planets whose heavy element contents were well constrained. All simulations use α = 1 × 10⁻⁴. Squares (circles) represent the ‘inner’ (‘outer’) formation regions. The points are placed at the initial position that led to the simulations most closely matching the observed heavy element mass. The error bars on the x-axis represent the width of the constrained possible formation regions of each planet, while the error bars on the y-axis show the range in the predicted C/O ratio within each region. WASP-84b is the focus of this work due to its potential observability and is marked with red points and error bars.