Late reply but: yes, ArcF study is required. NOM (Norma Oficial Mexicana) doesn't say you have to have one, but it says you need to use proper equipment. And there is only one way to know what the rating of such equipment should be, in order to be "proper".
I was looking at these last month, and I can tell you that Schneider is not the only one with LVPT. ABB has its own KEVA C, which has a lot of cabling options, SIEMENS is using their own version. I couldn't get these LVPT from either Schneider or SIEMENS as they won't sell them as separate...
