Modify Opigno Messaging app

Hello, I want to modify the functionality of Opigno Messaging app. Currently, user with correct permission are able to contact only the people who have taken classes or courses. (At least permissions at my Opigno instance are this way). On '' page, there are two fields 'Courses and Classes' and 'Select recipients' when a user is selected, his username is added to a hidden field which is present at the top. Is there any way to modify this flow and make the 'Courses and Classes' and 'Select recipients' fields optional? I tried to use hook_form_alter but it seems that I get the old form fields (the form is modified in Opigno Messaging app module). The best case for me will be provide a form where there are just 3 fields. To, Subject and Message. Is there any way by which I can remove or disable 'Courses and Classes' and 'Select recipients' fields and its functionality? If I disable the Opigno Messaging app module, I also need to disable some features related modules - Opigno Features OG Roles , Opigno Features Roles. Will there be any problem to current site if I disable these 3 modules? Thanks!