I think if I might be critical, the idea that the car graciously hands over control to you at a moment you are capable of catching might be a bit of a blind spot. The car could lose one of the signals it needs at an inopportune time and you would need a split second and correct emergency reaction to not spear off the road or collide with something. The physics of cars at highway speeds is awe inspiring, problems happen really, really fast.
I'm very curious at what level the restrictions operate. With every other manufacturer I've looked at, they're extremely coarse-grained; it's more like "is there a known long-time-horizon hazard in this area that is known to impair the system" than a "we mapped every lane and you need a database." I wonder if your I5 issue was a weeks or months-old construction area, for example. I haven't looked at Rivian much, though, and it could be totally different or extremely fine grained, there's no reason to suggest otherwise either.