THANK YOU FOR THIS PLUGIN!
I spent *HOURS* editing HTML, again and again, trying to get a complex instruction set done in a list of three levels.
I know HTML and I'm a pro. I diligently followed every new tip I could find to TRICK the WordPress editor into allowing me to use real for real HTML for lists the way it should be done.
Nothing worked and so I searched for a WordPress plugin to solve this and I found your plugin.
I'm going to share your plugin with everyone I know and install it on all client sites from now on.
THANK YOU! Now my page works the way nested HTML lists are supposed to work in spite of WordPress not supporting this.