When multiple zones overlap each other and at least two have the safezone option set to true:

• Dropped items fling out to the closest zone edge (and stops 2x farther past the edge).
  
  • Items dropped high above the zone will hit and roll over a larger superficial dome, as if the zone was 2x bigger than it's set to.
• Players when downed also get flung out of the zone. (2x past set zone edge)
• Players can pick up and place any deployable, regardless of related flag setting.
• Players can leave zones but cannot enter zones (2x past set zone edge), regardless of related flag setting.
• Players are immune to fall damage, regardless of related flag setting.

All of these traits are inconsistent when testing, working sometimes and not at other times even when nothing has changed. Except drop items flinging to the extended edge, that one is consistently reproducible. I'm certain there are more effects I haven't discovered.

These effects can happen even with two newly made zones with no flags other than their safezone option being set to true.
What is most perplexing is the apparent extended boundary of the zones, as if they're double the size they're set to.