taking time and looking back at stuff...
www.yoursite.com/moodle/mod/someplugin/mod_form.php (some place in file) $this->standard_coursemodule_elements(); = what loads up common stuff for an activity / resource when you goto edit it.
searching further....
www.yoursite.com/moodle/course/moodleform_mod.php is were function standard_coursemodule_elements(){ is created.
looks like it would be easy to add an " IF / THEN " statement within the function.without having to edit multi core files of plugins. to add additional options on edit pages.
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i do believe i got my hands on some older code some were along the lines (or just plain initial confusion reading over moodle code, very possible). were moodleform.mod.php -> standard_coursemodule_elements() function was all placed in renderer.php and/or mod_form.php or some other file. and stuff was "hard coded" into each mod/someplugin/somefile and each plugin was saying hey, i support this feature or saying hey i do not support this feature