Like all Universal basic income concepts, the problem that needs solving is individuals creating more than one account ( AKA sybil attack) biometrics seem like the only solution unfortunately. I have reposted your post on https://www.reddit.com/r/CryptoUBI/
Also of interest, I own ubicoin.com if wan to do something with this idea.
Biometrics fails because you need to verify the person. Biometrics merely generate a number and that number can be easily faked.
https://www.fastcodesign.com/3065564/a-synthetic-fingertip-for-unlocking-your-phone-in-gloves
A better solution is to just make the person certify life to a licensed notary public once a year, and then just get a bunch of notaries on board to manage all that.
Within the Duniter software, you can choose how many certificates you need to enter the community (web of trust)
Web of trust does not work because you need a web to identify people, thus nobody can ever enter. And ID needs to always work even if you have no connections.