Rated 2 out of 5 stars

Don't know how well this plugin works. The dialogs read like broken English.

This review is for a previous version of the add-on (10.0.4). 

B
I know there is never enough information but, I started adding internal help ( fully localized) did you check that out?
images a listing of all the ContextMenus as well as some option details. the extension has lots of permutations
and I agree it is not always obvious.
I would be happy to answer questions in the repository:

https://github.com/thundernest/import-export-tools-ng/issues
Christopher