I did not have to look very far for this example. Many lamp work fancy beads from Venice, whether for European jewelry applications or African & other trade, have air bubbles of various sizes. So I disagree with this part of your assessment.

I also disagree that finding sets of 19, or even 25 or more together indicates "not Venetian". The African traders typically have hundreds of strands of identical bead sets for example, including some very rare ones. And many antique necklaces are being sold today with intact sets of identical beads.

How did you conclude either one of these points applied to these beads in particular or any Venetian beads in general?