In Canada, when executing a missed approach from a non-precision CDA approach you are permitted to descend up to 50 feet below the MDA.
I don't know if this is a general rule yet but it has been approved for air carriers who use constant descent angle to be at MDA at the visual reference point required to complete a landing in a normal configuration.
Just make sure that you don't start any lateral maneuvers until after the MAP!
There are still a lot of instances where it is far more reliable to level and stabalize at MDA well befor the MAP. Mountainous terrain for example where local conditions can vary from one end of the runway to the other and a circling approach with lots of options. (Local knowlege may be required.)
VRT