Simply put, what's is generally in the job description of a co-writer? I've heard of the term, though I've never heard of the situation in an explanation that was real clear.
The situation I'm thinking of is if you can handle characterization fine for general plot related things (for example a trans woman's plot completed plotted out), but one may have difficulties with the romance angle, assuming aromantic isn't what you're going for.
Lately with current stories (after my last three novellas) it seems like the need for this is becoming more obvious. Not because I can't write romance, but I'm slightly unaware of practical realities in terms of romance in comics. I'm manly familiar with romance insofar as specific manga I've read in my teen years.
Like I have a very limited perspective of romance, and mainly write non-traditional romance. Such as the realities of dating a girl with hypochondria thinking she's developing dementia in a more current story. But in general I find romance to be something of a difficulty for me. I'm more used to middle grade novels where romance isn't really a thing beyond hand holding and maybe cheek kissing.