Maybe a few of them could have been brought over by the Nestorian monks that snuck the silk worms out of China for Emperor Justinian. The introduction of the Blast Furnace would certainly make a big difference if it was brought to Europe in the 6th century instead of the 13th. Paper making, because of it's artistic and commercial properties, might be something more likely than blast furnace designs for the monks to bring with them and would certainly add another source of revenue for the empire which would have the knock on effect of making book production easier which could certainly have some interesting consequences.