will tend to continiue to keep phase jumping to the next system even if the escorted ship has already phased jumped back to the first system.

even if both ships enter the same system at the same time

ie

if ships are being built in a and the escorted ships in c and both phase jump into b and reach the system at the sametime or sometimes even if the escorted ship has already reached b in front of the escorting ship

the built ships will phase jump to c