Slow wp-admin due to uncompressed photos?

Hello, my backend (wp-admin) is very slow when rtMedia plug-in is installed. When I activate it site speed is normal.

I wonder if it is because of uncompressed photos. I have discussed this issue with premium support before and they acknowledged this issue. They created a github entry you can read here.

Media uploaded via the rtMedia Uploader are not compressed like their WordPress uploader counterparts. This results in the WordPress media library displaying downscaled versions of full sized images, instead of compressed thumbnails. This increases the page load lime considerably, especially when using the “Grid” view.

Does anybody else have such issues? What could be done?