Additional Age Groups can be added by the User, however, AGB does not currently recognise non-binary for classification purposes so either they would have to be outside the classification scheme or they would need to be assigned a lookup value (this connects the tables) of either Men or Women as appropriate.
You could therefore have an age group of say Non-Binary U16 which is how they would appear in the scores, but for the classification scheme to operate you would need to assign a lookup value of either Men U16 or Women U16.