One more thought that might make a difference here. Try adding this to functions.php of a child theme or in a custom plugin:
add_shortcode( 'cs_no_preview', function( $atts, $content = '') {
return did_action( 'cs_element_rendering' ) || did_action( 'cs_before_preview_frame' ) ? '' : $content;
});
Then update your forms to be wrapped in the shortcode:
[cs_no_preview] Embed code here [/cs_no_preview]
That should be enough to prevent them from outputting in the preview frame. You’ll lose the benefit of seeing those forms while previewing in the builders (and Theme Options) but it will hopefully prevent React from being overwritten by that script.