How to request - Updating an embedded image in a PDF using Actions but not all actions are recorded

Give this a trial… It does a save as which is much safer than overwriting… At least you still have your originals should I get something wrong…? I did test but only with 3 files…

#target illustrator
function replaceImage() {
  
          var i, doc, fileList, inFolder, outFolder, opts, pic, rep, rip, saveFile, uIL;
          inFolder = Folder.selectDialog( 'Please choose your Folder of AI PDFs…' );
  
          outFolder = Folder.selectDialog( 'Please choose a Folder to save AI PDFs in…' );
  
          pic = File.openDialog( 'Please choose your replacement Image…' );
          if ( inFolder != null && outFolder  != null && pic != null ) {
                    fileList = inFolder.getFiles( /\.pdf$/i );
                    if ( fileList.length > 0 ) {
  
                              uIL = app.userInteractionLevel;
  
                              app.userInteractionLevel = UserInteractionLevel.DONTDISPLAYALERTS;
  
                              for ( i = 0; i < fileList.length; i++ ) {
  
                                        doc = app.open( fileList );
  
                                        rip = doc.rasterItems[0].position;
  
                                        rep = doc.placedItems.add();
  
                                        rep.file = pic;
  
                                        rep.move( doc.rasterItems[0], ElementPlacement.PLACEBEFORE )
  
                                        rep.position = rip;
  
                                        rep.resize( 31.414, 31.414, true, true, true, true, 100, Transformation.TOPLEFT );
  
                                        doc.rasterItems[0].remove();
  
                                        rep.embed();
  
                                        opts = new PDFSaveOptions();
  
                                        opts.pDFPreset = '[Illustrator Default]';
  
                                        saveFile = File( outFolder + '/' + doc.name );
  
                                        doc.saveAs( saveFile, opts );
  
                                        doc.close( SaveOptions.DONOTSAVECHANGES );
  
                              };
  
                              app.userInteractionLevel = uIL;
  
                    } else {
  
                              alert( 'This Folder contained NO Illustrator PDF files?' );
  
                    };
          };
};
  
replaceImage();