Absolutely.
You're the captain of the ship when you're driving. Try going into the scales with a violation, and tell them, "my dispatcher said it was fine".
Let me know how that works, and also tell me how much your ticket was.
A hot load doesn't take priority over DOT laws, or safety. You need to get comfortable with the idea of planting your flag and sticking to it. Because you WILL be tested. Dispatch cares about dispatch, not you.
I used to butt heads with dispatch and on-road about leaving late because I wouldn't leave until my trailers had load bars or the straps secured, as the law requires. I would tell them if they could get the hubs to do their jobs, and secure the loads, I wouldn't be late, and for a week or so, the loads would get secured and I would be on time.
And then it would go back to normal, no more secured loads, but they stopped asking me why I was late, because they knew and they knew I wasn't leaving until my loads were legal.
In typical UPS logic, they seem to prefer me leaving late than making the hub do its job. Whatever.