Hi urbanty,
I’m not sure about exclude_tags, I’m currently working on wordpress 3.31 and the_advanced_excerpt version 4.1.1, I did take a quick look in the plugin script, it seems like exclude_tags is not in the array anymore? or I might be wrong. But, this is the way that I found out how to filter the html tags. You can use allowed_tags and put in the tags you want to display your excerpt.
<?php the_advanced_excerpt(“length=20&allowed_tags=p,a”); ?>
Hope this information helps ??
Cheers,
Xavien