iframe code gets deleted

In version 3.9.8, the iframe code gets sanitized and just disappear completely. Luckily I have the backup of the 3.6 version of your plugin. When I use it to add iframe codes to post, it worked like a charmed without getting sanitized by WordPress.

Can I get the same functionality in the future update please? I really like your plugin and has been using it very often. I noticed some people posted the same issue and resolve it by passing iframe code to some php file so that it would not get sanitized. However, I don’t think it is doable for me.