This may ruffle some feathers but if that brings out discussion about the value of this trait, that's a good thing.
I think Secondary Sexual Characteristics should be removed, because it's not pulling its weight and it's too vague to operate on when creating, reading, or searching for a profile. If it's doing something useful, we should replace it with a more clear and direct trait. There are other gender traits and multiple other traits for sexual characteristics, so I'm not sure where that leaves this one needed.
These thoughts came after we earnestly discussed revising the description of its both category. We probably got a better description of it. But it also became clear there's very little that's really a distinctly male or female secondary sexual characteristic — the stand-out ones are facial hair and breasts and there is already a trait for one of those. It's either trying to say too much or too little or not saying it in a useful way.
In practice I think people are using this to indicate they're overall male or female, regardless of plumbing. Unless they're a female with a very masculine build or vice versa. Hermaphrodites are theoretically meant to use it to indicate whether they're male or female hermaphrodites, but they can almost universally indicate that with breasts or lack thereof. I'm not sure how meaningful it is for trans men or women. I know with a straightforward cis character I can pretty easily just tick 'male' or 'female' in all the gender/sex traits, but that's about the only case I'm clear on.
I suggest we remove SSC, and use sex, mental gender, and breasts (or lack thereof) to express what's going on, including for hermaphrodites.
The alternatives I see are: do that but give male/female hermaphrodites separate Sex categories. Or, rename SSC to something like "Body Gender" that's just straightforward and clear that this is overall what you really are, along with a rename of Both to Androgynous. I am not sure either of these are more optimal though, and we can revisit the Body Gender thing later. This suggestion doesn't cover actually doing these.
If you have thoughts on the matter, please express them.