And how is one supposed to get by at $1000 a month? That doesn't even cover rent for most people.
GMI or NIT are comprehensive economic policies that effect everything from aggregate consumption to demand for labor. The goal is not to see how much you can give away. You're trying to raise income. A small minority of people acquire their income via transfer payments so you're obviously not going to scale comprehensive economic reform around the exceptionally poor. We've been doing that for a half-century. It's counter-productive.
The goal is to create a surplus of jobs at the bottom end of the pay scale so the US can import labor responsibly, export jobs responsibly, and raise wages. Adjustments can be made for people with limited access to the labor market, like single mothers, by giving additional income for qualifying children.
