> I personally prefer keeping the existing means-tested programs but counting UBI as income when considering eligibility, such that with growing UBI [0] you eventually reach the point where the income floor is above the eligibility level for the means-tested programs, allowing them to be discontinued.

It might be better to directly subtract the benefits from any such program from the UBI. Then the only people who will even bother signing up for the other programs are the people whose total benefits from the existing programs exceed the UBI, which should be almost nobody. Then having demonstrated that fact in practice, those programs can be discontinued for lack of any real use and the savings can be used to provide slightly more UBI.