We had used the filedownload plugin/snippet for the book and video downloads on our www.spiritualoutreach.com web site. The counter worked perfectly fine and is one of the reasons we were disappointed to not be able to use the plugin because of blocking problems on very large downloads - something we were never able to fully resolve.
It has been quite a while since we used it and I do not have our configuration on file but I do recall a problem where the template variable for the directory did not properly handle inheritance and had to be manually set on every page. I don’t think that affected the counter; I think that prevent the proper finding of files but you could try it. Sorry I can’t be of more help - John
$downloadFileURL = ($modx->config['site_url'].$downloadFolder . '/' . trim($_GET['d']));
$downloadFile = realpath($downloadFolder . '/' . trim($_GET['d']));
header('Location:'.$downloadFileURL);
exit; // CxH Added for Browsing purposes
if($fp = @fopen($downloadFile, "r"))
[!FileDownload? &getFolder=`assets/files` &tplList=`filedownloadtpl`!]
<tr class="fd-file fd-alt"> <td><a href="assets/files/content-brief-example.pdf">content-brief-example.pdf</a> <span style="font-size:80%"></td> </tr>

From what I understand that is correct.
If I understand you correctly, then, this snippet will not force the download, just present the files in the folder?
The plugin is required to force the download dialogue box?
No you don’t understand correctly. The snippet presents a link for you to download the file with your browser directly from the web server. This interaction is controlled by MIME types and your browser says, "look, it’s a PDF file" and then decides to open the file directly in your PDF viewer application after silently downloading the file to a temporary location. This is how all file downloads work in browsers.
If I understand you correctly, then, this snippet will not force the download, just present the files in the folder?
The plugin is required to force the download dialogue box?