I am working on a CMS. One of its functions is the editing of HTML \"chunks\" in a WYSIWYG editor that are displayed as individual pages.
I have an area in the CMS w
If you take TinyMCE for example, they use also an iframe, I think they had the same problems like you. I use it in my backend and on some pages 4 iframes. I don´t see any performance problems.
With TinyMCE it is possible to compress the functions you need (in PHP, JSP, .NET and Coldfusion), this gives you a great speedboost.
Think twice, bevore you write your own WYSIWYG editor, the others are well tested and have a bunk of very good plugins for nearly every need.