Since posting this: I chatted with Rivian and got the response I was expecting: "some SC's have public charging stations and are available, look at plugshare". They aren't going to admit that they have restricted/employee or level 3 stations that are available to us. I may try to call the Ft...
I was at the Madison Heights SC today to pick up my R1S and the customer service tech offered to put more complimentary charge on (had already added 14% before I got there). He said they had level 2 and DC charging available. I asked if all sc had level 2 and 3 available. He said he thought so...