There's a topic about
The Great Monarch in particular, here on Cathinfo where you can find some interesting texts.
I didn't find anything in Irlmaier's visions about the great monarch who's a French Frank uniting the entire Europe and even recapturing Jerusalem. What you mention sounds like a certain Emperor with divine help at the end of time, whilst Irlmaier foresaw a period which is not the end of time.
Irlmaier foresaw an humble and ordinary German-speaking man coming from Austria (or Bavaria which is NOT Franken) who would be crowned by the pope (so be an emperor or at least a very important king) but wear his national costume Lederhosen! :-) Irlmaier suggests that this emperor doesn't originate in the nobility but in the ordinary folk which doesn't surprise if we look at the massive corruption of the remaining nobility. So Irlmaier's emperor is an unspectacular man with Lederhosen, but still a good catholic man, and I think this is great.