We have something similar although only in certain dialects of danish. The following is a valid sentence meaning the island in the river: æ ø i æ å

Ø - the 27th letter of the danish alfabet
Ø - the danish word for island

I mean being romantic or sexual carries some other connotations and meanings making them ambiguous in many situations if used as the antonym to the asexual and aromantic label.
I don’t really care what words are used for it but I find the allo ones useful as they are the most commonly understood ones and are unambiguous.