Script a pathlist to use when creating an Indesign book

A few days ago I wrote this script that creates a book from InDesign documents located in the selected folder (including it's subfolders). If the book with the same name as the selected folder already exists, the script just opens it.

var myFolder = Folder.selectDialog( "Select a folder with InDesign files" );
if ( myFolder != null ) {
     var myFiles = [];
     
     GetSubFolders(myFolder);
     
     if ( myFiles.length > 0 ) {
          var myBookFileName = myFolder + "/"+ myFolder.name + ".indb";
          myBookFile = new File( myBookFileName );
          if ( myBookFile.exists ) {
               if ( app.books.item(myFolder.displayName + ".indb") == null ) {
                    myBook = app.open( myBookFile );
               }
          }
          else {
                myBook = app.books.add( myBookFile );
                myBook.automaticPagination = false;
                for ( i=0; i < myFiles.length; i++ ) {
                    myBook.bookContents.add( myFiles );
                }
                myBook.save();
           }
     }
}

//=================================== FUNCTIONS =========================================
function GetSubFolders(theFolder) {
     var myFileList = theFolder.getFiles();
     for (var i = 0; i < myFileList.length; i++) {
          var myFile = myFileList;
          if (myFile instanceof Folder){
               GetSubFolders(myFile);
          }
          else if (myFile instanceof File && myFile.name.match(/\.indd$/i)) {
               myFiles.push(myFile);
          }
     }
}
//--------------------------------------------------------------------------------------------------------------

Is that a list of paths (folders) which have to be scanned for every InDesign file in each, or a list of full paths to every single ID document?