Spot on advice again Dave. I understand your concern about a DGSA possibly getting walked over by an unscrupulous boss, but I was alluding to container haulage in my reply. There is no rail freight terminal or dock that will accept a hazardous load unless all paperwork and markings are correct. So it is pointless to cut corners.
In my experience nearly all the companies that I have dealt with do not have a resident DGSA, but use a consultant, so if there are any issues, he is an independent source of advice, which is offered in company contact details.