Whether identifying as black, female, Latinx, queer, trans, Native American, Asian-American, Arab-American, disabled, Muslim, biracial or any combination thereof, playwrights traditionally marginalized in the theater face a second problem if their work finally ekes its way to the stage. They often feel pressure, from critics and producers, to depict globally and endorse unequivocally their diverse communities — which is bad for them and worse for their stories.

Call it vexation without representation.

Leah Nanako Winkler isn’t having it. In a note to the script of “God Said This,” which opened on Tuesday at the Cherry Lane Theater in a bumpy ride of a production, she urges directors and actors — and, by implication, audiences — to see the multiethnic family at the heart of her play as “deeply flawed, complex people” who are “not defined by their race.”

Nor by much else, it seems. She sets out not only to bust stereotypes about submissive Japanese-American women but also to rescue hick Kentuckians, intolerant Christians, “tiger moms” and even the dying from the broad brush of caricature.

Mission accomplished, though at a cost to coherence. Hiro, the daughter of a Japanese mother and a white American father, is no meek good girl; she’s more like a hot mess. The last time she came home to Lexington from New York — a disastrous visit that was the subject of Ms. Nanako Winkler’s “Kentucky,” seen in New York in 2016 — she nearly ruined her sister Sophie’s wedding and wound up having sex with an acquaintance on the roof of their old school.