Final chirp masses and orbital periods in the MESA simulations of dB20. Top: Final properties assuming direct collapse into a BH (with its mass at carbon depletion) and ignoring mass loss due to (P)PISNe. Each dot indicates the final result of one CHE simulation. Systems above the dashed gray line have merger times longer than the age of the Universe and are marked with a lighter color. Results are shown for their grids with metallicities of log₁₀Z = −2.375, −2.5, −2.75, −3, −3.5, −4, and −5, with the labels indicating their approximate values in terms of the solar metallicity (taken here to be Z_⊙ = 0.017 as in Grevesse et al. 1996 for consistency with the definition used in dB20). Bottom: Same as the top panel but after including the impact of (P)PISNe as described in Marchant et al. (2019).