The free version is pulling partial content, so can the Professional version pull the complete content? Is this something you can verify?
The free version works with the feed contents, whether they have partial or full content.
When you use the Full Content Add-on, the plugin goes to the source site and takes the content from there.
If you are having problems with the pulled content, you can make a config file to “tell” the plugin where the article content is for each domain and to indicate which tags remain and/or strip. See https://etruel.com/question/pull-content-source/
It’s based in xpath and there is some tutorials and examples inside Full Content Addon. But in most cases it’s not necessary.
If you want to be sure that a particular feed works with Full Content, you can send the feed URL to us and we’ll test it.