If you have multiple iframes, it's going to load kibana multiple times. That's just how iframes work. Why not embed the entire dashboard instead of each visualization individually?
By "not responsive" do you mean "not optimized for mobile devices" or "too slow"? If the former, there's an open ticket you can add your thoughts to: https://github.com/elastic/kibana/issues/2563. If the latter, you can open a new ticket with the issue you're experiencing: https://github.com/elastic/kibana/issues/new. There's no way to get around the fact that each iframe will load the page anew.
Apache, Apache Lucene, Apache Hadoop, Hadoop, HDFS and the yellow elephant
logo are trademarks of the
Apache Software Foundation
in the United States and/or other countries.