Comparison of the formation timescales for the four different SFH models with respect to the ground truth values from the TNG50 simulation. Each marker represents the formation time of a galaxy in our sample, color-coded according to the corresponding SFH model. Star-forming galaxies are indicated with stars, while quiescent galaxies with points. From left to right: Time for 20% (t₂₀), 50% (t₅₀), and 80% (t₈₀) of a galaxy’s stellar mass formation. The four models include the spatially resolved model from pixel-by-pixel SED fitting with a nonparametric (orange) and parametric (pink) SFH, the integrated SED fitting with a nonparametric SFH (yellow), and a simple τ model within Prospector (blue). The measured bias (average offset μ) and scatter (standard deviation σ) relative to the ground truth from TNG50 are indicated in the legends of the panels. The formation times inferred from the spatially resolved and integrated nonparametric SFHs are in best agreement with the ground truth values.