If you think the unit is poor don't use it for shooting deer. If you can't identify don't shoot. All these rules are a minimum standard anyway if you require a higher standard use one.I am sure some of the top end units will give out a reasonable heat record of the background that was not in the response. They are calling for a minimum standard of thermal unit to be used. There are some really pour quality units that wont give true back drops. If the legislation goes through as is then it will mean any one can use any unit.
Red stags above the tree line on mountains are not really the situation that night shooting is for.