One more comment...if a demon were to manifest in the middle of the consecration, I would think the correct action would be to place the host upon the altar, turn towards the demon, and rebuke him in the Name and Power of Christ. It would be, I think, the equivalent of Jesus exorcising on the Sabbath: sending a demon back to hell and freeing one of God’s children takes priority over the sacrament. You can always have the Eucharist, but demons don’t always provide an opportunity to be exorcised.
I think that asking Jesus to take up the demon from the possessed person or asking Jesus to have his angels bind and remove the demon and to try to then convert it from its demonic ways is preferable. Why: perhaps the demon does not want to actually return to satan &/or hades; thus the exorcism is welcomed rather than fought against. Does this always happen, probably not, but worth it for the sake of the possessed being relieved of the demon.
Excellent comment...