You use the placard to see what your max MAP is. If when you lift to the hover, you have the same MAP - you have zero performance margin. This should correlate with your assessment of AUM and density altitude on the IGE and OGE hover graphs. If you think you are well under the MAUM for IGE or OGE hover according to the graphs and you are still pushing the MAP limit in the hover then either check your figures or call the engineer.