Does anybody know how to make the brand new FlexiPDF 2017 (http://www.softmaker.com/en/flexipdf) work with Directory Opus preview pane?
It would need to install either a Preview Handler or an ActiveX component. If you can view files in Explorer using it then it should just work in Opus automatically.
I don't see any mention of viewing files in Explorer on their list of features, however, so my guess is it's not supported.