The majority of wines that I have encountered with VA are from VC tanks. This makes sense, since the Acetobacter bacteria consumes ethanol in the presence of oxygen and forms acetic acid. Likewise, Lactobacillus consumes residual sugar in stored wine, creating acetic acid. So maybe an accidental Lactobacillius inoculation occurs while the wine is open to air and fruit flies?
SO2 is critical when suppressing the establishment of VA producing bacteria. And, as you know, oxygen exposure eats away free SO2 and helps open the door to a myriad of wine quality issues.
It seems like the only safe way to store wine in a floating lid tank is to keep pressure on the inflatable gaskets. You can do this by running air hard- lines around the tank room with flexible drops fitted to the air inlet on the gaskets with quick- connects. Then you set the regulator to the pressure rating stated by the lid manufacturer as appropriate for maintaining a seal.
Or just use portable, stackable, (33% more) space- efficient, TranStore tanks from Custom Metalcraft and gas the headspace. Gassing tanks full of clean wine with the appropriate SO2 level is the best way to prevent VA production.