For the composer
I think the name is not perfect.
He was Hungarian (Austria-Hungary) and the “official name” would be “Kálmán Imre” (the Hungarian-way: Surname Firstname). This is as it is in hu-Wikipedia.
However, he live and worked most time in Austria and also in the States and in France. The most common variant of his name is “Emmerich Kálmán”, the Germanic variant of Imre, in the usual western style (Firstname Surname), like it’s also used on several Wikipedia sites: https://de.wikipedia.org/wiki/Emmerich_Kálmán, https://en.wikipedia.org/wiki/Emmerich_Kálmán, https://fr.wikipedia.org/wiki/Emmerich_Kálmán, … Also many (most) other sites use , Emmerich Kálmán, e.g. https://www.britannica.com/biography/Emmerich-Kalman
He composed primarily for German operettas.
Since he was Jewish (and he changed his name to Kálmán - not sure if official, but it looks so) I’m not sure it felt like a Hungarian. Maybe he felt more like an Austrian, since he worked a long time there.
If it’s correct, he (also) had US-citizenship (see https://www.musiklexikon.ac.at/ml/musik_K/Kalman_Familie.xml). I don’t know which other citizenships he had.
For me it’s also not clear, if he changed is first name officially or used Emmerich just without an official document.
So one question is: Is someone Hungarian by birth? By citizenships? By a long working period?
If Hungary would be his correct classification then IMHO also the Hungarian style Kálmán Imre should be used.
Otherwise – and this is my favorit version, because it seems to be the most common version – it should be changed to Emmerich Kálmán.