1) It’s illegal to speed in any lane at any time even while passing. Here it is straight from Utah highway patrol: “A misconception of the passing lane is that it is the "fast lane", we have no such lane. The speed limit in each lane is 70 mph in most areas of the state, there is not a flexible speed limit in each lane.”
2) It is illegal to not give a three second following distance at all times.
3) It’s illegal to camp in the passing lane. That means not getting over as soon as you have an opening. I always get over as soon as I have an opening. I never camp on passing lane.
As long as folks follow all three of those laws I have no problem with them. I try to do the same. See you on the road. 😘