If you want to make basic income a political possibility, you need data. This is something which can be tested at small scales, and relatively cheaply. We should definitely do that, scaling the test size up as we go. Hell, a private organization could do this. Where's George Soros when you need him?
As I said, I'm skeptical that this idea will work. It would however be fairly trivial (and cheap!) to carry out an experiment which could convince me otherwise.
Frankly, anyone who objects to the notion that we should spend $50 million or so to test the idea before implementing it on a large scale is a complete fool.
I think you overestimate the importance of data to most people. It might swing some intellectuals, but generally people are very good at finding reasons to discount data they don't agree with.
Data would be nice so we can evaluate if a basic income is a good idea or not. But is largely irrelevant to actually making it a political possibility.
The data isn't available, at least not where you've said it was.