I don’t know if I get it correctly, but the elephant in the basic income’s room is heavy taxation, no matter how it’s implemented, either as demurrage, transaction fees or both (and I don’t understand how a VAT could be implemented with blockchain)
E.G. a US basic income of $1000/month requires ~25% of GDP to be put into it.
If it is attempted as taxes in official currency it will be resisted politically.
If tax is attempted in new crypto-currencies, it will make “capitalists” less motivated to even care to sell goods in such currencies.