I believe all of their suite here are king bed. I would write hotel now so they will save you a rollaway in the living room.
As a diamond and family of 4, kids age 10 and 14, we were able to stay in the suite even the room limit does say 3.
Did you stay in this property? Their Regency Suite is pretty small, was there 5 years ago. HR Sha Tin has bigger suites. Or HR TST, but then Regency Executive Suite or Presidential one