"As a byproduct of digesting this biomatter, the black soldier fly larvae produce frass, which is essentially insect waste."
"Even with 0% frass, he saw flowering and pod growth in plants potted entirely in Martian soil."
"Mendoza found that exceeding anything greater than 50% frass would destroy the plant's ability to grow but adding 10% frass to the Martian soil was the optimum amount for plant growth."
There's no information on growth rate delta between 0% and 10%.
I expected this article to say that plants do not grow naturally in Martian soil, but that the frass provides sufficient nutrients for them to grow. Instead, I learned that plants do grow in natural (simulated?) Martian soil, that an amendment helps an undefined amount, but that too much of the amendment kills the plants. I didn't find that especially compelling.