1) You don't need MFMP to know allumina band Emissivity
2) What they measured was total emissivity and if they not used pure Alumina then what they measured have nothing to do with Lugano
3) In one of their experiments they are trying to measure the emissivity of a body that was in an oven. Because the oven is a cavity is natural that the emissivity of any material result very near to the black body emissivity.
And BTW the argument of emissivity factors cancelling is true and your is disinformation.
Is not a coincidence that after a long time of silence you came out now with that.
What is required to measure total emissivity is a total radiometer and a strong vacuum.