In Fig. we present shape and branching metrics corresponding to the micelles formed in the CAPB / SLSar 0.67 simulations (the same systems as Fig. for consistency). Additional figures showing shape metric evolution over time for all sampled ratios at pH levels from 3.9 -4.7 are supplied in the Supporting Information. Note that the presented images show the average shape and branching behaviors across the ten replicate simulations. For a CAPB / SLSar mole ratio 0.67 at pH 3.9 we see an early majority of spheroid micelles decrease rapidly with time as both rod-like and then, slightly later, extended structures such as WLMs and 2D branched morphologies appear. This appearance of extended structures corresponds to the formation of branching in the simulations. The initial increase in rod-like micelles is reversed as the fraction hits ≈ 0.6, at which point extended structures begin to develop. This occurs as rods extend into WLMs, with rods extending across periodic boundaries in predominantly one direction. More significant branching is then observed as WLMs form branches that shift the extended structures across periodic boundaries in multiple dimensions. This pattern of behavior is repeated for mole ratio 0.67 at pH 4.3 (Fig. ) where there is a slower decrease in spheroid micelles, a corresponding slower increase in the rod-like and WLM micelles, and hardly any 2D extended structures appearing (a very small degree of 2D extended shape is present in the final reported time frames corresponding to a small degree of observed micelle branching). Again, the onset of extended structures (WLMs in this case) appears as the fraction of rod-like micelles crosses ≈ 0.6. This is again repeated in Fig. with the rates being slower once again with almost no WLMs (or branching) being observed. In the case of the mole ratio 0.67 at pH 5.1 system the dominant shape remains the spheroid with a minority of rod-like micelles forming. No WLMs or extended structures appear in this case. Note that the rod-like fraction of all the systems presented display an early peak and then steep decay in the very early time scales (in approximately the 250 DPD time units). Through visualisation of the morphology produced we attribute to the behavior of very small micelle aggregates just above the cut off of N mic = 6.