Not seen a Mechanic Exemption, commercial truck, commercial license, CDL in driver's possession all strikes as to exempted. Only time not on the ELD would be bending wrenches.
Energy Companies are playing with 'Unwritten Clauses' where the field personnel are NOT using the truck in truck service but to drive point A to B(conveyance), then they have a problem when the first piece of anything is laden in the bed, tools, parts, debris then becomes a CDL qualified. Had the argument as to my having a CDL years past, they stated I did not NEED one as NOT hauling anything, then the brown shirts noted Commercial Plates, Corporate name on door, weight rated truck licensed truck not car two plant operators got tickets AND points on license which the company WOULD NOT PAY FOR. They opted to drop us into small machines then whined as we could not haul anything we needed to, they stated WE needed to Know the law and applicability as well were responsible not themselves and left it as that.