Good point made.
In my case I have a mechanical self-leveling loader, a lifting capacity of nearly 3x the bale weight, a properly ballasted tractor and a backplate on my forks that is 3 feet tall. Furthermore, I am an experienced forklift and tractor operator, so I can see level on the forks and can see and feel instability of the load. In my set-up and with my experience, there is no risk what so ever of a bale flopping over the backplate or off the forks while working on reasonably level ground.
All that having been said and understanding the legal warnings that is required when dealing with equipment of any kind, the original poster will have to assess for himself the conditions under which he is using his equipment and his competence with the equipment to determine if he will be performing a safe act.
My comment about bale spears being dangerous on FEL is two fold: 1. If a bale is poorly formed or weathered, the bale may come apart or slip off the spear. The FEL just gets the bale that much higher in the air when it happens. 2. The operator is farther away from the tip of the spear on a FEL vs. 3 pt, thus he is more likely to make a depth perception error and pierce something besides the bale or not get the bale well seated on the spear or worse yet slip while seating the bale.
A rotational head bale squeeze is the best tool for the job, but for 30 bales a year and for the size of the unit he is using, it is impractical.