Hey Credo,
thanks, we’re doing our best :)
Regarding your question: this is not possible via the theme’s settings back-end, yet quite easy to achieve via some custom CSS:
#nav-primary ul li ul { left: 0; width: 100%; }
You might also consider grouping the data and creating second-level submenus instead of adding a lot of items into the first-level submenus, as this might not always be the best solution in terms of usability and user experience.
Sincerely,
Andrii / Satori Studio