The Ancestry and MyHeritage DNA genetic groups sometimes successfully distinguish between Ashkenazic sub-populations such as Litvak versus Galitzianer. For example, MyHeritage correctly assigns my father to its primarily Belarus and Lithuania clusters and my mother to its primarily Poland and Ukraine clusters. They also got assigned several additional Ashkenazic clusters that are more generic or mixed, and a portion of my father's DNA to their "Sephardic Jewish-North Africa" group. But as early uploaders we didn't have to pay anything to receive these estimated assignments.
Jill Whitehead has a good idea that if you really want to pay for additional analysis, a specialist might be the one to choose instead.
There aren't any pure Sephardic individuals alive today, genetically speaking. Modern Turkish Jews are a combination of Sephardic Jews, Romaniote Jews, Italki Jews, and Ashkenazic Jews. Modern Bulgarian Jews are likewise a Sephardic-Ashkenazic mix. Modern Moroccan Jews are a combination of Sephardic Jews with pre-1492 Jews including Berber Jews (the French author Julien Cohen-Lacassagne isn't entirely wrong on this point). Modern Syrian Jews are a combination of Sephardic Jews with pre-1492 Middle Eastern Jewish ethnicities. The only way to reliably identify a portion of DNA as Sephardic is to find it matching non-Jewish communities of Sephardic descendants that were isolated from practicing Jews for centuries, such as those from the Azores, the Philippines, Peru, or Cuba. None of the big companies tried to do it in that way, hence all the false positives and false negatives to their "Sephardic" categories.