I bet, that initially, only a few slots will be made available to see how senior the bases will go. As long as ARAPA officers will bid for those vacancies, more base slots will be made available. As soon as it hits HKPA officers seniority no more slots will be available. At that time commuting rosters on COS18 will be made available.
Dan,
Basings can not be on POS18. As the base areas have labour laws and negotiated CBA's all those new base vacancies will enjoy the applicable CBA of the respective base area.