Individual add-ons belong to individual developers. They are allowed to set whatever contact preferences they want on the add-on pages. I believe that one provides multiple ways to get in touch with the developer.
However, I still don’t think the add-on controls mouse sensitivity, so I’m not sure contacting the developer again – since you already have in the support thread Image Occlusion Enhanced [Official Support Thread] - #181 by ukhkbale – is worthwhile.