The percentage of the Hispanic Asians vs. non-Hispanic Asians in the US will be so small, well, I just think it is not necessary to make such a distinction.
I agree, it's not. The only people who would care if there were significant health differences between "Hispanic Asians" and "non-Hispanic Asians" would be the people with the problematic health distinctions! For example, I can imagine there being a higher incidence of diabetes among Hispanic Asians, if they adopted the high-sugar diet of many other Hispanic immigrants.
Demographic researchers get confused having to deal with "Hispanic," because it's purely a cultural/historical characteristic, not a biological one.