The problem with the IMC exam is that it's part gospel, part fact.
The biggest issue I found is the "add 150 or 200 feet to the DA/MDA" thing. This is not in the ANO but only in the AIP. So it's not a legal requirement and IMC holders are legally entitled to descend to the minima on the plate. But the IMC exam treats the AIP recommendation as the legal limit, and bases the correct answers on that.