Single, prescription 4 figure-of-merit curve for a Plummer cluster interaction with ﹩{N}_{c}=8192,Q=0.5,{\rm{\Delta }}{x}_{{\rm{init}}}=4{R}_{c}﹩, and ﹩{\rm{\Delta }}{z}_{{\rm{init}}}={R}_{c}﹩. Contrast the quadratic-like behavior here with the one-sided trough seen in Figure 1(d). Interactions with the smallest impact parameters investigated here tend to enforce lower limits to the softening length regardless of other initial conditions or cluster density profile.