The Motorola radios are typically sold to industry and programmed for licensed frequencies, really expensive compared to a vhf radio that you program yourself. There is some issue of legality with radios opened up for licensed industrial frequencies, or there always was.
My understanding is commercial vehicles "must call" on resource roads, but have a responsibility for public safety. They should be given the right of way but do not have it unless marked by road signs.They would be liable if their speed pushed you off the road, if you could prove it.
It is just common sense to try to be cautious and call in your kms , I do when I can.
Non commercial vehicles do not have a requireent to call in, as much as it makes sense.