How to not remove featured image from content?

Fantastic plugin, but I can’t find a way for the filter add a featured image but not remove it from the content. Is there any way to do this or will it just always remove the image it uses from the content of the post? Issues arise when the text refers to ‘the image below…’ but the image is only present at the top of the page.

https://wordpress.org/plugins/faf/