In reply to Rich.

Clicking it the DFW button again in the corner will disable it if you don't wish to use it after trying it.

Also I like the idea of improving the editor though I would push more towards having an option for a front-end editor over DFW. I like the idea of wordpressdotorg plugin https://wordpress.org/plugins/wp-front-end-editor/

But then again if the WP API gets added to core that will hopefully get a maybe more options for front-end editors or ones that come built into themes.

Just hope more maintained flexible ways for front-end editor open up this year.