Circularization timescale τ_e (in billion years, logarithmic color scale) as a function of the modified tidal quality factors of the BD and the star for TIC 9344899. Black contours mark τ_e = 1, 3 Gyr (solid) and 10 Gyr (dashed); the white contour indicates the system median age; the red curve shows the boundary where tides in the companion and in the star contribute equally (τ_e,2 = τ_e,⋆). Contours are nearly horizontal in both panels, indicating that τ_e is chiefly set by stellar dissipation over plausible $Q_2^{\prime }$.