Ancient Greek apostrophe marking elision

[James Kass via Unicode]

Perhaps I'm not understanding, but if the desired behavior is to 
prohibit both line and word breaks in the example string, then...

In Notepad, replacing U+0020 with U+00A0 removes the line-break.
U+0020 ( δ’ αρχαια )
U+00A0 ( δ’ αρχαια )
U+202F ( δ’ αρχαια )
It also changes the advancement of the text cursor (Ctrl + arrows), 
suggesting that word/string selection would be as desired.  (U+202F also 
does this and may offer a more pleasing appearance to classisists by 
default.)

Wouldn't it be best to handle substitution of U+00A0 for U+0020 at the 
input method / keyboard driver level where appropriate, so that 
preferred apostrophe U+2019 can be used?