TSS 3.0 cruise control works just fine, regardless of which state borders that you are operating within. Traffic Jam Assist is awesome! TSS 4.0 will be even better! But there are definately times when it would be safer not to use it. Like on the road between 101 and highway 1.
Miss Daisy is always on cruise control when we travel. But, if in hilly and very curvy areas in the Appalachian’s, I can be advantageous to not use cruise control, and allow the vehicle to slow down a few MPH going up hills, and around mountain curves, potentially saving gasoline when TSS kicks in the turbo, when on cruise control. This was especially true in my 2015 long wheel base, extended body, tall roof Transit with its 3.5L twin turbo ecoboost engine. That thing would pull a loaded 14’ cargo trailer right off its wheels.