I would be interested in reading Hormisdas' condemnation.  The best that I've found was vague reference to a re-iteration of pseudo-Gelasius which, again as I read it, is establishing canonicity v. declaring heretical the doctrine / dogma of the Assumption.  The book on the infancy of Jesus is also on the list of apocrypha - do you think Gelasius was condemning the Natavity?
In stating my opinion re pseudo-Gelasius, I follow that of those more expert in the topic than myself.  I have looked for contrary opinion contemporary to those which deny his authorship and have found none.  I'm willing to go where facts point, regardless of the outcome.  But there is a tough-row-to-hoe if one is choosing the Assumption as proof against papal infallibility.
Send me Hormisdas and I'll gladly look at it (Latin or English, if possible; French or German, if not; if you only have a Greek reference, as I've commented to others before, it will be a struggle for me to read in any reasonable time).