Given there is now the ability to copy a webpage, presumably one answer to this question about editing live webpages is:
copy / duplicate the page the page to be edited, making the copy page not live
edit the copy page,
copy the old page URL,
make the revised copy page live with the changes you've made,
delete the old page
swap the new URL for the old URL
This to me would seem an acceptable workaround, do you agree?