Redshift evolution of the stable reverse-mass-transfer LGRB event rate density for the IllustrisTNG metallicity and star formation history. The total potential population is indicated in black, while the dashed red line shows the intrinsic LGRB rate from Ghirlanda & Salvaterra (2022) with the best-fit parameters based on observations. The red shaded area is 10% to 20% of this rate. The five green shaded lines indicate the rate density for an energy limit of 10⁵¹ erg and different η_ϕ.