Yes, Amazon already offer a Sidewalk SDK as part of AWS IoT offerings. I didn't even think about the cost angle, which is a really interesting point (although,

Yes, Amazon already offer a Sidewalk SDK as part of AWS IoT offerings. I didn't even think about the cost angle, which is a really interesting point (although, I think ISPs have an argument against the Amazon devices here still as it's effectively connection sharing, which they also usually ban in ToS). My consideration was just for the customer sales pitch, which is "your IoT devices Just Work magically."