For example one would be able to decide that the "custom quote" page is in_navigation but only shows in the footer navigation. The different navigation areas can be specified in settings.py, as those are typically statically defined by the website design, and then a staff member can select which navigation area(s) is appropriate for the specific page in the admin with a multi-select. The render_menu template tag would need a new argument to have a simple slug passed through to the in_navigation queryset method such as 'header', or 'footer', or 'mobile', etc.
Example:
settings.py
from django.utils.translation import ugettext_lazy as _
...
FLUENT_PAGES_NAVIGATION_AREA = (('header', _('Header')),('footer', _('Footer')))
...
template.html
...
{% render_menu max_depth=1 template="fluent_pages/parts/menu.html" area="header" %}
...