I do not currently have this marked as installed...since I can't get it to work.
I have made the file edits as posted in your readme file.
I have uploaded the externalredirect.php file to the forum root.
I have installed the product.
I found your product in vBoptions and have the following settings:
- Use no follow attribute is set to "no"
- All other settings are set to "yes"
I'm not getting any redirect message at all.