Not sure why you do not want to use embed tags? Visualizations and dashboards are complex and visual by nature and cannot be served as a response payload to curl. After you retrieve visualization/dashboard names and IDs via curl, you can easily dynamically embed iframes by swapping out the ID in the embed code.
<iframe src="http://your-kibana-instance/app/kibana#/dashboard/dashboard-id-here?embed=true&g=()" height="600" width="800">