// GF method: http://www.gravityhelp.com/documentation/gravity-forms/extending-gravity-forms/hooks/filters/gform_init_scripts_footer/
add_filter( 'gform_init_scripts_footer', '__return_true' );

// solution to move remaining JS from https://bjornjohansen.no/load-gravity-forms-js-in-footer
add_filter( 'gform_cdata_open', 'wrap_gform_cdata_open' );
function wrap_gform_cdata_open( $content = '' ) {
    $content = 'document.addEventListener( "DOMContentLoaded", function() { ';
    return $content;
}
add_filter( 'gform_cdata_close', 'wrap_gform_cdata_close' );
function wrap_gform_cdata_close( $content = '' ) {
    $content = ' }, false );';
    return $content;
}