In illustration 1 (red) we see the zones that are safe from a Home shooter. (All shooters positions are marked with a dot in the appropriate color.) This allows players coming off the board in the first seconds of a breakout to hesitate or delay in order to shoot an additional lane. The lane options are inside out (wide for a runner), cross field, or outside in (edging). Edging employs one of the blocking bunkers to provide an element of the unexpected as the shooter clears the edge in order to lane the chosen target. OTB that's usually Home and is frequently done in conjunction with a wide runner to neutralize (suppress) the effectiveness of the Home shooter.
In illustration 2 (green) the DZs have shifted. The green shooters are in DZs relative to a Home shooter but not necessarily to anyone else. It is important to understand both sides of the DZ coin. Not only who can't see a particular DZ but who can as well as what new lanes and new DZs are in play as all the players on the field are taking their primaries.
In illustration 3 (blue) the shooters are wide. While it is basically correct to say that areas you can't see can't see you need to keep in mind a couple of related factors; how edging works and the proximity of the blocking bunkers. The edging principle focuses on the boundary between what can be seen and what can't and depending on how close the critical blocking bunker is to one player or another that boundary tends to a) get a bit fuzzy and b) can offer opportunities for blind shots. For example, the checkered area emanating from the snake brick reflects two things; the brick is a low bunker which makes it possible to shoot the corner cake either coming off an edge or blind into the deeper area away from the brick. The same applies to the blue area between the widest snake-side pin and the TCK that feeds the snake. Level changes and bunker position can modify effectiveness of a DZ.
In illustration 4 (all colors) any place where all three colors overlap represent DZs that are blind to all the positions illustrated. To expand on the primary utility of the DZ it can be; 1) a secondary laning position when you need to find more effective ways to put paint on your opponent with reduced risk, 2) offers all the benefits of playing behind your gun with dramatically reduced risk when shooting specific lanes or zones whether attempting to contain movement or suppress shooters, 3) gives the experienced player time to read & react to how any given breakout is unfolding and aggressively push the play.
Next time you walk a new field spend some time with your teammates identifying the DZs you think you can play and make a specific effort in practice to try them out and get comfortable playing them and before you know it you're playing a whole new game.