Well, I did not realize that it was a minefield and that your question was a rhetorical one... You can trust me to walk confidently.
Seriously,
as I wrote above (but you jumped overboard before reading it), I agree with your "preserve entity" solution for
nnbsp and it's OK for me. This way, the
nnbsp is not blinking but displayed and
identified in Code view.
I think that representing
nnbsp in code view by an undocumented white space like today is wrong because it is misleading. The
nnbsp, like the
nbsp, has to be identified at a glance. Why?
For nearly "historical" reasons. Sigil has been plagued by the
nbsp display question for years. Some weeks ago, I opened a thread showing that even the \xa0 hexadecimal suffered from it: using a regex with \xa0 in the replace field is enough for destroying all
nbsp and transforming them in undocumented white spaces. So if one finds the same kind of display for the
nnbsp, he will probably think they too have been destroyed.
A proposal
Could you consider extending and enabling by default your satisfactory "preserve entity" solution for the
nnbsp as well, thus this character could safely be identified at a glance by all users in code view?