Underfire:
The pilot needs to know that the DA includes only a 50 foot momentary descent. Most aircraft cannot go from approach config to GA and only descend 50 feet.
I think the airplanes that would go more than 50 feet below DA are the exception rather than the rule. I base this on the premise that the rule requires the decision to be complete at DA, not to start the assessment at DA. Having said that the only penalty for going below DA is an increased climb gradient for the early stage of the missed approach.