Great and important point being raised here - how to deal with UBI and inflationary pressures that may emerge.

My additional thoughts: I think the issue with inflation and UBI is that if everyone is given x$, then everyone has more money to bid up certain services - especially housing. Thus, for example, rents would increase by a significant proportion of the UBI transfer. We already observe this in the subsidized housing market - since mortgages in the US are subsidized, house prices are higher than fundamentals (rent flows). I think this is the issue with any money based universal system. Possibly a goods based one would be better, or a targeted benefits system.