While using the visual custom fields advanced location rules editor I can't limit the custom field display to the home.php and/or front-page.php. Could you add functionality, to limit the locations to those pages in the visual editor, like so:
'include' => [
'relation' => 'OR',
'ID' => [get_option('page_for_posts')],
],
'include' => [
'relation' => 'OR',
'ID' => [get_option('page_on_front')],
],
?