I don't understand your point with regard to charity. What's your objection if this is charity?
I understand your concern about messy legislation but is that an argument against it? I see your point, though. I'm guessing, possibly wrong, that the people involved in this have considered or at least will consider how this will be implemented and will fund lobbying to try to get this done as cleanly as possible. I realize I'm making some assumptions here but people aren't going to invest boatloads of money in testing a concept than just let it fail during deployment.
There's no universal definition of basic income and it certainly won't be so straightforward once it goes through the meat-grinder of legislation.
It's cash on the barrelhead to the poorest of the poor from outside organizations. That's charity.