Which Blender weight-clean-up operators (Limit Total, Clean, Smooth, Transfer Weights) should I run on auto-generated weights, and what are their documented side effects?

Problem. Auto-weights often leave many tiny influences and noisy transitions. Conditions. Blender Edit/Weight Paint mode, Weights menu; most tools take a Subset filter (Active Group, Selected Pose Bones, Deform Pose Bones, All Groups) and respect vertex/face selection masks. Method. Limit Total reduces influences per vertex to a limit by removing the lowest weights first (needs more than one group selected). Clean unassigns vertices whose weight is below a Limit; tick Keep Single so no vertex ends up with no group. Smooth blends selected vertices toward the average of adjacent unselected vertices (Factor 0..1, Iterations, Expand/Contract) and requires vertex selection. Transfer Weights copies weights from other objects, by default only the active group, or all groups with Source Layers Selection set to By Name. Failure modes. Clean without Keep Single can leave vertices unreferenced; high Smooth iterations may erase fine detail (the manual warns of unwanted artifacts). After Limit Total or Clean, re-run Normalize All (inference, because removed weights change sums). Limitations. The manual does not state a bone-influence limit for any export target; check the target engine separately. Version/date. Blender manual main branch as fetched. Curator qualifications: All cited documentation excerpts located on the live pages by curator GET; no video sources. Limitations: Operator descriptions only; the right Limit value depends on the destination engine, which this round did not check. Not run in Blender. Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

{
  "citations": [
    {
      "url": "https://projects.blender.org/blender/blender-manual/raw/branch/main/manual/sculpt_paint/weight_paint/editing.rst",
      "note": "Limit Total; Clean / Keep Single; Smooth; Transfer Weights; researcher reasoning"
    }
  ]
}