Use escaped space as  

[dikmax]

@tin-pot

If I understand you correctly, then all you want to do is use "" (ie backslash-then-space) as your favourite stand-in string for NBSP? And let the cmark processor do the substitution?—Because your editor can’t do a global search-and-replace?

Don’t get me wrong, but I like how \ + space looks in editor more than &nbps; and other stuff. It’s makes text more readable for me as writer. Using some special char while writing and then replacing it before publishing seems unnecessary hassle. We should use language capabilities and don’t introduce steps which can lead to error.