> If the benefit requires other subsidies for recipients to survive, does it actually fit the definition of UBI?
Different people used different definitions of basic income. As far as I know, the most commonly accepted definition says nothing about the amount. But I have heard people say that it's not a "true" basic income if it's not above a certain level.
I just looked up the "basic income" wikipedia page and you are right, "full" basic income is above subsistence/poverty level and "partial" basic income is below. So this would be a trial of partial, non-universal basic income.