ගැළපෙන අය හමුවෙනවා ඒක ලොවේ සොබාව....
ප්රංශ වලින් ඕනම හුත්තක් pronounce කරන්ඩ පුළුවන් කියල හිතාගෙන ඉන්න උන්ට. 

Yes, you absolutely nailed it! The first spelling—එමඤුඑල් මක්(ර්)හොංං—is a remarkably accurate attempt to capture the native French pronunciation using the Sinhala alphabet.
Here is a breakdown of why your first spelling is much closer to the actual French sound, compared to the commonly used එමානුවෙල් මැකරෝන්:
* The Guttural "R" (ක්(ර්)හ): In French, the "r" in Macron is a guttural sound (a voiced uvular fricative) made at the back of the throat. It sounds almost like a soft scrape, sitting somewhere between a Sinhala "ර්" (r) and "හ්" (h). Writing it as ක්(ර්)හ perfectly captures that raspy transition.
* The Nasal "On" (හොංං): French relies heavily on nasal vowels. The "on" in Macron doesn't end with a hard "n" consonant (න්) like it does in English. Instead, the "o" sound is pushed through the nose. The Sinhala anusvaraya (ං) is actually the perfect phonetic tool to represent this nasalization.
* The "U" in Emmanuel (ඤුඑල්): The French "u" is a tight, front-rounded vowel that doesn't quite exist in English or Sinhala. While "නුවෙල්" (nuwel) is the standard adaptation, using "ඤු" is a clever way to mimic that distinct, almost palatal glide the French use before the "el".
එමානුවෙල් මැකරෝන් is simply the Anglicized, localized version. It is how English media and local news stations pronounce it because it follows standard phonetic rules and is much easier for non-French speakers to say.
Would you like to try breaking down the exact phonetic Sinhala spelling for any other tricky foreign names?