The purpose of the custom front page is to provide a format in which to display any object or image as the center-of-attention.
This may entail a few bumps and work-arounds for some, yet it is a part of On The Side Theme styles and should be easy to configure as follows:
You can simply add a Widget to the "Center Widget" To override any Home Page content.
If you do not have a widget set for "Center Widget" then your normal content will display on your Home Page.
If you add a widget to the Front Page and your theme is set to show Posts on the Home Page then the widget will NOT over-ride your Posts.
A great solution is to put the widget: "Recent Posts." into Center Sidebar.
This gives you your pages on the left sidebar with plenty of open space to
show image background while listing your Posts as a Table of Contents.
Side Menu Instructions
The default widget, on the left, will show your Pages and a Log In Meta box.
Creating a new "Left Sidebar" widget from WP Admin will take precedence over these defaults but, still leave the Pages widget, underneath the logo, to display your blog pages.
This Left Sidebar menu is called from wp-nav-menu and IS the main menu.
With setting theme to show A static page (as Home page) - Shows Home Page unless you set a Center Widget.
With setting theme to show Your latest posts, you get Your Latest Posts, even if Center Widget set.