Average lifetimes against (solid red) collisional disruption and (solid blue) PR drag e-folding times (a/ȧ for q = a(1 − e) = 100 au and e = β/ (1 − β); see Sect. 4.3) of objects in our ACE run with a circular parent belt (e_b = 0.0). The dashed and dotted black curves show size-dependent timescales for full precession cycles caused by planets with M_pl = 5 × 10^-5M_∗ = 32 M_⊕ at 30 and 70 au, respectively. The two short lines of the same styles illustrate the corresponding times to precess just to e_b = 0.1.