I understand your concern but to answer it I think a necessity with a BI would be stricter regulation around credit. If you offer a BI and people can take the BI while simultaneously accepting predatory credit offers, the prices of things will go up, BI acceptors will get duped by banks and credit card companies and the BI money gets funneled back to those large institutions while BI-receivers pay for their financial mistakes.
This doesn't quite sit right with me, because it seems like the underlying argument is "those who benefit from BI don't know how to spend their money, so we have to protect them from spending it poorly". The end result of that line of thinking is targeted social programs, which specifically do not permit people the chance to mis-spend money. How would BI + strict regulation and oversight be substantially different from the entitlement programs we have today?
Actually we could just refuse to enforce contracts in which future BI income is leveraged for debt. That's already done with certain kinds of retirement assets.
