I'm trying to change the thickness and the radius of the sheet metal folder (not the sheet metal features inside the sheet metal folder). Consequently, the changes in the folder data will propagate to the sheet metal features hence why I'm doing it.  I tried the following code:

' Preconditions:
'       (1) Part document containing sheet metal part is open.
'       (2) Sheet-Metal feature is selected.
'
' Postconditions: Default bend radius value is doubled.
'
'-----------------------------------------------
Option Explicit
Sub main()
    Dim swApp                   As SldWorks.SldWorks
    Dim swModel                 As SldWorks.ModelDoc2
    Dim swSelMgr                As SldWorks.SelectionMgr
    Dim swFeat                  As SldWorks.Feature
    Dim swSheetMetal            As SldWorks.SheetMetalFeatureData
    Dim bRet                    As Boolean
    Set swApp = Application.SldWorks
    Set swModel = swApp.ActiveDoc
    Set swSelMgr = swModel.SelectionManager
    Set swFeat = swSelMgr.GetSelectedObject5(1)
    Set swSheetMetal = swFeat.GetDefinition
    
    Debug.Print "Feature = " & swFeat.Name
    Debug.Print "  Thickness (Before)  = " & swSheetMetal.Thickness * 1000# & " mm"
    
    ' Rollback to change default bend radius
    bRet = swSheetMetal.AccessSelections(swModel, Nothing): Debug.Assert bRet
    
    ' Double the default bend radius value
    swSheetMetal.Thickness = 50.8 / 1000#
    
    Debug.Print "  Thickness (After)  = " & swSheetMetal.Thickness * 1000# & " mm"
    
    ' Apply changes
    bRet = swFeat.ModifyDefinition(swSheetMetal, swModel, Nothing): Debug.Assert bRet
 Debug.Print bRet
End Sub

But for some reasons it doesn't work although Bret is true at the end. When I edit the sheet metal folder, the thickness value is not changed. Any help would be appreciated