At the risk of teaching granny to suck eggs:
There are two ways taught to deal with an MDA.
1. Fly level at MDA until the MAP. You are correct, the examining limit for this method is -0/+50'.
2. My previously mentioned add50' to MDA and treat as a DA. Though this 50' would increase with aircraft weight. Basically you need a margin which would allow you to initiate the GA and not bust your MDA. So you fly a stabilised descent to the Virtual DA then go around. This may be before the MAP, depending on how well you have judged your descent path.
The second method inevitably could lead to you missing out on the last 50' of cloud base, but is much safer than levelling off fully configured. Indeed for commercial operators EU ops made it mandatory.
Of course the basics still apply. MDA is absolutely not to be busted. DA is where the GA must be initiated so in a large enough aircraft this could be busted whilst engines spooled etc. this is ok.