In fact cash-grant villages were more likely to grow their own food than control villages. A large part of the cash grants were spent on procuring better seeds and upgrading their livestock.

It's not clear that that the villagers were "more likely" to grow food for their own consumption rather than growing cash crops to sell. But if you want to dive into that level of detail, I would like to see the original report with all the data. I don't particulary trust this UNICEF report which looks a bit biased to me.

but believe it or not, 'advanced societies' do have poor people, and lots of them, and experiments like these hint that a universal basic income cannot simply be dismissed as 'eliminating incentives and leading to mass starvation.'

I'm not saying that UBI is a bad idea. I'm not saying it's a good idea, either. At this point I don't know -- I can see both good points and bad points and it's not clear to me how they will balance out in real life. I suspect the details of implementation will make a lot of difference. Those "pilots" that you mention are much too limited to draw any conclusions.

And please go easy on straw, no one claimed that UBI would lead to mass starvation. A full-blown scheme of no property, no money, etc. is likely to and that's what the "will starve" claim referred to.