What I want to add is to be able to select the two surface bodies that are at the same locations of the originally selected faces, knit them together, then select the body that is created and body keep/delete (keep) it. I do not have a lot of coding experience so I attempted to use swModelDocExt.SelectByID2 but this would not consistently select the same faces that I originally had selected.
Any help is appreciated, thanks!
 

Prereq: select two faces of a solid body

Dim swApp As SldWorks.SldWorks
Dim swModel As SldWorks.ModelDoc2
Dim SelMgr As SldWorks.SelectionMgr
Dim swPart As SldWorks.PartDoc
Dim swBody As SldWorks.Body2
Dim swFace As SldWorks.Face2
Dim swFaceRef As SldWorks.Face2
Dim swObj() As Object
Dim swRef() As Variant
Dim intArraySize As Integer
Dim i As Integer
    
Sub main()

    Set swApp = Application.SldWorks
    Set swModel = swApp.ActiveDoc
    Set SelMgr = swModel.SelectionManager
    Set swPart = swModel
    tol = 0.00001
    
    If SelMgr.GetSelectedObjectCount2(-1) <> 2 Then
        MsgBox "Select exactly two faces. The first cannot fully contain any feature, i.e. a hole."
        Exit Sub
    End If
    
    Set swFaceRef = SelMgr.GetSelectedObject6(1, -1)
    swFaceNormal = swFaceRef.Normal
    
    'Get persistent IDs of selected objects
    intArraySize = SelMgr.GetSelectedObjectCount2(-1) - 1
    
    ReDim swObj(intArraySize) As Object
    ReDim swRef(intArraySize) As Variant
    For i = 0 To intArraySize
        Set swObj(i) = SelMgr.GetSelectedObject6(i + 1, -1)
        swRef(i) = swModel.Extension.GetPersistReference3(swObj(i))
    Next i
    
    '------
    swModel.ClearSelection2 True
    
    SetSurf (0)
    swModel.InsertOffsetSurface 0#, False
    
    SetSurf (0)
    swModel.InsertDeleteFace
    '------
End Sub

Function SetSurf(i)
        Set swObj(i) = swModel.Extension.GetObjectByPersistReference3(swRef(i), Empty)
        swObj(i).Select2 True, Empty
End Function