737OPR, not a dumb question at all.
The ICAO PANS OPS definiton of MDA does not allow descent below that altitude; however not everyone follows PANS OPS thus what the US does may not apply to JAR-OPS. There are differences in the obstacle clearances provided by PANS OPS and TERPS. (FAA allows descent below MDA for VNAV ?)
With the advent of a stabilised approach / constant angle approach, and VNAV, JAA have debated (still debating?) the overall safety case for using MDA as a ‘DA’.
The anti CFIT advantages of stabilization etc are judged to outweigh the very small increased risk in descending below MDA during a go-around; one study has shown that there is no change to the overall risk in an operation when all aspects are considered.
It is possible that JAA OPS guidance material has been issued, even included in the stabilised approach criteria, but I do not have a copy of JARs to hand. If I recall correctly, the issue was left open so that each operator could decide on a procedure (add 50ft or not) in conjunction with their National Aviation Authority.
Thus your question should be put to flight ops management as to what the policy and procedure is; – and have they discussed it with their NAA.