Fair enough. We should make sure software including screen readers properly support Unicode in a useful way. Lack of support in the present is not a reason to avoid emoji. And math notation is already very non-ASCII so arguments related to plain text mode debugging are not applicable. There is probably an argument to be made about color blindness.

But overall my argument is that emoji are not a solution to the problem of very limited naming options for things in math, lack of significance of the symbol used and that of homonymity . The solution is using words. And those words may contain Unicode characters. And alias longer names to symbols on case by case basis.