I'm using Word 2016 to write articles that must keep certain words on the same line. Therefore, I work with a lot of non-breaking spaces. The articles eventually go to print (or PDF), meaning there must be absolutely no visual difference between a regular space and a non-breaking space. I sometimes also send them as Word documents to editors, so there has to be no difference between the spaces when the file is opened in Word, either.
Word 2013 mostly eliminated fixed-width non-breaking space, meaning that when you typed Ctrl+Shift+Space, you got exactly what I need: a variable-width non-breaking space, which behaved just like a regular space. That's logical: a space is a space, and a reader looking at a page has no reason to get a different visual result when it's a non-breaking space. It was different for purely historical reasons, but Word 2013 at least partly fixed that.
Word 2016 reverted to fixed-width non-breaking space, which is precisely what we are trying to avoid. This occurs not just when typing Ctrl+Shift+Space, but also when inserting any Unicode character of this family, including U+00A0, U+2009 and U+202F. These either don't work (the line breaks), or they are fixed-width. Similarly, U+2007 is too wide (also fixed-width).
So far, I found a single solution: typing U+FEFF, then regular space, then U+FEFF again. U+FEFF is "Zero Width No-Break Space", so it does not produce a space itself, but keeps on the same line what's before and after the regular space. Visually, this produces an identical result to a variable-width non-breaking space.
The problem is, first, it's cumbersome to type; and, second, when the file is edited in Word, you get a strange, interruptive feel - it's three characters instead of one, two of which are invisible, etc. If it was possible to merge this character sequence into a single keyboard shortcut, that would be helpful, but still wouldn't resolve the second problem.
I read the other threads online for the last few days; none helped (expectedly, many resort to the historical parables). So, what is a streamlined way to get a variable-width non-breaking space in Word 2016? Either a Unicode character I haven't yet discovered, a compatibility setting that would make Word 2016 behave like Word 2013 in this regard, or any other solution. Many thanks for the help.