Memes of Production

I still don’t see how UBI wouldn’t result in inflation of some sort

Inflation isn't just driven by the bottom dollar of the poorest spender. If the US surplus production + imports exceeds the demand created by UBI, prices would fall rather than rise. If US consumption diminished overall while UBI rolled out, inflation would fall. If the national economy raises taxes on the wealthy while it increases spending on the poor, you won't see inflation. You'll see resource reallocation.

I might point you to parts of the country that lack consumer infrastructure - food deserts, being the most prominent example. A neighborhood without a grocery store will experience higher cost to access basic food and food services than a neighborhood with one. UBI expands the incentive to build supermarkets in high-population low-income neighborhoods. The net result of new infrastructure in underdeveloped communities would (somewhat paradoxically) drive prices down, in the same way the advent of Big Box Retailers in major metro areas reduced consumer goods prices during the 80s/90s.

Capital improvements to areas with large populations of people with money to spend can generate a profit on the improvement while still reducing the cost of living for individual inhabitants.

Ask anyone who has moved from a rural underdeveloped neighborhood to a highly developed urban one, and you'll find out the appeal is often lower overall living costs relative to wages - shorter commutes, cheaper goods and utilities, more public amenities. UBI can have the same impact on large low-income communities.