It does the trick, and I prefer about:home to about:newtab. My only request is that instead of going to an intermediary address (moz-extension://.../html/newtab.html) set it to the default. It works well other than that.
Thank you for your feedback. There is nothing what I can do because there is no other way to override the new tab page, I have to call an extension script and this script has an URL. You have to suggest Mozilla to implement a better solution. ;)
