In "Project -> Tasks" Kanban view for each stage there are buttons ("+") to create tasks for that stage. These buttons are for "quick create". But the user asked to have additional button "Create" to open a form for "New task".
How to add additional buttons that open task creation form? Each button should appear next to "+" button.
From the point of view of functionality the module Optional quick create is what your user wants. If you select avoid_quick_create for the model project.task there is still this quick create dialog, but after setting a title and pressing 'add' the form appears. When the user wants to quick create, he just presses 'ok' and he created the object quickly. And when the user wants to set details, he stays in the form. The module works for Odoo 11 also
