This is in response to your answer to this question.
I’ve heard it said that once a person intends to desecrate a consecrated host, Christ’s presence departs. Given the scenario the original poster brings up (desecration of the host), that would seem to make much more sense to me. Christ willingly becomes present in the Eucharist. Why could He not willingly leave? It’s not as if He is conjured and then trapped until the bread deteriorates.