>> My bet is that they included such language to calm fears regarding the random insertion of the plasmid into the genome. Such a random insertion could be very problematic, as you may imagine. <<
The “without a requirement of incorporation” phrasing does not do a good job of calming. Not having a requirement for incorporation into the genome does not imply that the introduced VEGF gene/promoter does not get incorporated.
If a random insertion were in fact to happen, just how bad would that be?