I did a box trailer last summer with Oracal Calendared with air-release. (I think it was 3751, but I'd have to look it up) Laminated with 210 lam (however I've read here many times you can put cast lam on calendared vinyl, but not the other way around)
My understanding of cast vs calendared is cast is more "conformable" so you can stretch and pull it, and it will stay (with heat) Calendared not so much
Cast will also last longer.
So.... other than last longer, what's the advantage of cast for a big flat surface? My trailer did have rivets, which were indeed a problem, even with heat, it was hard to keep the vinyl down tight around them. Other than that, it still looks perfect.
Its a competitive world out there!.... just because a solution is not "perfect" doesn't mean it's out of the question. I think the key thing is the customer is aware of the choices / differences.