I did a CX659 and CX714 (about 13hrs on ground) last weekend. HK ground staff printed both boarding passes.
I entered T1 security and immigration with my HK printed boarding pass. Went lounge hopped BA (closes at 23:00), QF Biz, QF First (closes at 23:00), QR Premium (closes at 02:00)
I left QR Premium lounge at 23:45, walked to gate C21, there is a staff there asked which flight etc, take the lift downstairs and waited at the comfy bus lounge (lots of sofas). The bus came at 23:58, the bus stopped briefly at T3, then continued to T4. The bus ride was about 15 to 20 mins.
Note: no liquid over 100mL is allowed since you need to go thru security at T4. (very few people)
I then took the lift straight to the lounge level to check out blossom lounge, and CX lounge.