I’d tie it to the system scan as well, make impossible to search for a new jump route until the system scan is complete. That scan is going to take serious hours to complete only being reduced by having lots of pilots contributing dividing the total hours needed per system (which is set by the dev’s as not all systems are the same size)
It also follows the current game logic as all FTL jumps are done from ‘orbit’ so to establish the FLT orbit of the system needs it to be fully mapped. So the only valid jump route until the system is full mapped is the entry route, locking all exit routes as unplottable until the scan is complete.