A complete list of hooks can be found in the Hooks API documentation on GitHub.
For example, on Breakdance shape dividers:
add_filter('breakdance_shape_dividers', function ($dividers) {
$myDivider = [
'text' => 'My Divider',
'value' => file_get_contents(__DIR__ . DIRECTORY_SEPARATOR . "my-divider.svg")
];
$dividers[] = $myDivider;
return $dividers;
});