For each BHB formed, we plot the dynamical friction timescale (Δt_DF = t_b − t₀, top panels), and the total coalescence time (Δt_coal = t_coal − t₀, bottom panels) as a function of the initial distance between the progenitor galaxies (d₀). Data are colour-coded according to the initial eccentricity of the galactic merger. Note that we chose to use log₁₀(1 − e₀) to make the colour gradient clearer, so the colour bar goes from high (yellow) to low (blue) eccentricity values. Panels on the left refer to LR runs, while panels on the right show data from their HR counterparts. Empty circles, squares, and diamonds represent the first, second, and third binary in each tree, respectively.