Upper: effect of temperature and/or magnetic field on the M–R relation. The WDs formed by accretion onto a 0.45 M_⊙ HeCO WD are further cooled to various T_e and the M–R relations for a specific T_e are shown. Nonmagnetized cases are shown with a dashed line with filled circle, and magnetized cases with a dashed line with asterisk. The ideal Chandrasekhar case is shown by a solid line. Low-mass outliers (S. G. Parsons et al. 2017; D. Karinkuzhi et al. 2024) mostly fall within the extent of these curves. The rightmost inset shows many more magnetized cases with various T_e for completeness. The leftmost inset shows the particular case of SDSS J123204.19+522548.2 (T_e = 8750 K: D. Karinkuzhi et al. 2024), confirming the magnetized WD model suffices to explain the data. Lower: the dependence of radius on T_e for both magnetized (filled triangle) and nonmagnetized (filled circle) cases of M = 0.55 M_⊙. Observed outliers shown therein are for 0.5 ≲ M/M_⊙ ≲ 0.6, taken from the ones displayed in upper panel. The ideal zero-temperature result is shown by a zone bounded by dashed lines. In the magnetic cases, the field is specified by the profile parameters η = 1.3, γ = 0.9 (defined in Appendix A).