The herm and maleherm tags are an issue.
To start, 'herm' has multiple different usages within furry and porn that are inconsistent with e6's definition. When someone's personal definition is 'all altersex with boobs' and another person's is 'all altersex' and another person's is 'gynomorphs' that leads to inconsistent tagging that needs to be watched and cleaned up regularly. The term itself and the implications the tag has do not give clues how it is supposed to be used.
On top of that, herm/maleherm does not leave room for characters/species that are totally androgynous or their other sexual characteristics are unshown or ambiguous. A genitals-only image tells you a character has a vulva AND a penis, but does not tell you what their bodyshape is otherwise.
Finally, 'herm' has historically been used as a derogatory and hurtful term towards real-world intersex people.
So, a proposed alternative is bigenital. The one con is that it might be interpreted as 'two sets of any genitals', but context of use and implications should be able to enforce the correct use of the term. At the very least, it's more intuitive than 'herm' is.
'Bigenital' on its own doesn't have the same body type split as herm/maleherm, and this is fine for its own tag- it would serve as an umbrella term for both cases as well as being a valid tag for androgynous/ambiguous cases- but this split IS useful for searching and blacklisting. I'm not certain how best to split the tag, but I can think of a few options:
-male_bigenital and female_bigenital (con: potentially implies male/female should be added, however this con already exists with maleherm)
-masculine_bigenital and feminine_bigenital (con: maybe someone interprets it as manly vs girly?)
-bigenital_andromorph and bigenital_gynomorph (con: potentially implies andro/gynomorph should be added, similar issue exists with maleherm)