Saving to distinct MIF version not possible in script

In the following script MIF is saved in the version of the current FM. For example, if FM-16 (2020) is active, then the script save as MIF-16.

KLD_Z.SaveDocToMif = function (oDoc, saveName) { // ===========================
/*            Save document to MIF at the same location as the original document
Arguments     oDoc            Document to be saved
              saveName        File name e.g. oDoc.Name + ".mif"
Reference     Rick Quatro in 
              https://community.adobe.com/t5/framemaker-discussions/
              creation-of-extra-dialogue-in-framemaker-for-templates/td-p/13664579
*/
var params, returnParams, j;                                  //  1
                                                              //  2
  params = GetSaveDefaultParams ();                           //  3
  returnParams = new PropVals ();                             //  4
  j = GetPropIndex (params, Constants.FS_FileType);           //  5
  params[j].propVal.ival = Constants.FV_SaveFmtInterchange;   //  6
                                                              //  7
  oDoc.Save (saveName, params, returnParams);                 //  8
  if (FA_errno === 0) {                                       //  9
    return saveName;                                          // 10
  } else {                                                    // 11
    PrintSaveStatus (returnParams);                           // 12
  }                                                           // 13
} // --- end SaveDocToMif -----------------------------------------------------

However, I wanted to save as a distinct MIF version (say, MIF-14) out of FM-16.

For this purpose I changed in line 6 FV_SaveFmtInterchange to FV_SaveFmtInterchange140

This does however, not save at all (line 8). It results in reporting SaveStatus as FV_BadSaveScriptValue.

► How to save as a distinct MIF version similar to save as distinct FM-version?