The most important rule about wraparound is: there is no special rule. All processes work seamlessly across the map border. When a ship sits at the left border and moves to the left, it will appear on the right. When a minefield with 100 LY radius is 50 LY from a border, it will reach over the border, 50 LY into the opposite quadrant.
Caveat: There's one caveat to watch out for. When you set a very long waypoint ("1900 ly to the right"), the ship may move in an unexpected direction. PHost will always move ships along the shortest possible path to their waypoint, possibly using a wrap boundary to make the journey shorter.
Caveat 2: External add-on programs may not know about or respect the wraparound settings. Thus, they may move ships outside the wraparound region, and not modify their effects to take wraparound into account. PHost will move all ships outside of the wraparound region back into the region, but there may be other interactions that are not so easy to predict. Check with the documentation of the add-on program for any mention of wraparound support.
Sphere and PWrap: It is not recommended to use Sphere or PWrap with PHost. Although these add-ons also implement a wraparound universe, they can not deliver the full integration as PHost does. For example, minefields near a border will not reach into the opposite quadrant with these add-ons. You should definitely never use Sphere or PWrap when AllowWraparoundMap is enabled.
