RE:RE:Processing Plant coming to the USA. Depends how you look at it but technically Arizona is closer than Cobalt Ontario is by a couple hundred kms (crow flies however is like 2000 kms more than Cobalt) however you now have several government agencies you need to deal with transferring rare earth metal cross state and country lines (tax involvement, etc etc). The US is doing the same thing Canada is trying to do.
As the last 2 or 3 years has shown, all it takes is 1 partner in North America to get frustrated and any arrangement is held hostage. For a fledgling company, that is too high of a risk that your whole process will crumble when there isn't even an actual facility yet.
Generally speaking, manufacturers dont make deals with each other cross country and state lines unless they have an active division in said area. I.O.Us (aka memoriums of understanding) have difficulties sticking when companies arent held to the same rules in separate countries so to me, it would be very unlikely we would partner with something in the US which is trying to create a strictly US battery supply line (however, I have also seen worse happen!)
good luck to longs