My custom script UV Symmetry auto flip and auto welder.

check some implementation function see at below

  on flip_center_uv pressed do --UV 플립 버티컬 센터..
  (
   if (classof(modPanel.getCurrentObject())) != Unwrap_UVW then
   (
    messagebox "언랩모디파이어가 있어야 합니다." 
    return undefined
   )
   else
   (
    selectionSets["tempSel"] = selection
 
    sel = selection
   
    obj = #()
   
    for i in sel do
    (
     append obj i
    )
   
    for i = 1 to obj.count do
    (
     select obj[i]
     face = obj[i].modifiers[#unwrap_uvw].getSelectedFaces
     
     uvMod = selection[1].unwrap_uvw
     uvMod2 = uvMod.unwrap2
     selCen = uvMod.getSelCenter()
     uv_center_point = [0.5 , 0.5 , 0.0]
 
     obj[i].modifiers[#unwrap_uvw].unwrap2.scaleSelectedXY -1.0 1.0  uv_center_point -- 사이징 함수부.
    
     clearSelection()
     
     select selectionSets["tempSel"]
     
     for i in sel do
     (
      i.modifiers[#unwrap_uvw].unwrap.edit ()
      i.modifiers[#unwrap_uvw].setTVSubObjectMode 1
     )
     actionMan.executeAction 0 "40021"  -- Selection: Select All
     
     actionMan.executeAction 2077580866 "40015"  -- All Commands: Texture Vertex Weld Selected
     
     update $
    )
   )
  )