In addition, full, 100% automation doesn't seem likely to me. Service sectors of the economy may simply keep smaller human staffs in order to keep their hospitality atmosphere. Not enough to offset job loss in other sectors, but there are already plenty of businesses today that have a human element that don't _actually_ need them. It might even look like a luxury business model. No reason that will go away just because robots can do it better.
Trying to peg UBI to regional cost of living costs an incredible amount of money (the cost of living in the Bay Area has to be at least 10x the rural Rust Belt) and has practically no benefit (because all it means is people get the privilege of living wherever they want on redistributed money, rather than choosing to either live where they want and seek the means to afford it or living where its cheapest and costing society less in macrospect.
There already exist communities and retirement homes whose entire agreement with its residents is "give us your social security checks, we give you food shelter etc". If you know constant money is coming in, arranging your business around being super easy to use for that money is a very lucrative opportunity.
That's why I always clarify that an essential piece of Basic Income is that it is unconditional. Whether you're on the bottom rung of society or the top, employed or unemployed, basic income should be the same amount.
When the choice to get a job changes from "Well I'd lose my benefits" to "Well my basic income is no longer enough, I'll work part time", then state welfare no longer becomes as much of a trap. It can finally make strides towards lifting people out of poverty.