NBSP supposed to stretch, right?

[James Kass via Unicode]

On 2019-12-17 10:37 AM, QSJN 4 UKR via Unicode wrote:
> Agree.
> By the way, it is common practice to use multiple nbsp in a row to
> create a larger span. In my opinion, it is wrong to replace fixed
> width spaces with non-breaking spaces.
> Quote from Microsoft Typography Character design standards:
> «The no-break space is not the same character as the figure space. The
> figure space is not a character defined in most computer system's
> current code pages. In some fonts this character's width has been
> defined as equal to the figure width. This is an incorrect usage of
> the character no-break space.»
>
The mention of code pages made me suspect that this quote was from an 
archived older web page, but it's current.  Here's the link:
https://docs.microsoft.com/en-us/typography/develop/character-design-standards/whitespace

Quoting from that same page,
"Advance width rule : The advance width of the no-break space should be 
equal to the width of the space."

So it follows that any justification operation should treat NO-BREAK 
SPACE and SPACE identically.