| Protocol element | Physics-only arm | Plugin-assisted arm |
| Contact handling | Contact and friction only | Same contact model plus gazebo_grasp_fix |
| Paired trials | ≥30; identical seeds/poses | ≥30; matched seeds/poses |
| Primary outcomes | Success rate; drop count | Success rate; drop count |
| Motion outcomes | Task time; joint RMS error; peak oscillation | Same measures |
| Contact outcomes | Slip distance; contact impulse | Attach latency; false attach/detach |
| Reporting | Mean/SD or median/IQR; 95% CI | Paired difference and effect size |