For those interested, arrived a little early at t5a (equated to a 4hr layover), followed transfers to terminal 3, went through security no problem. The guy made us aware our flight was in 5 and we were in 3, said we were going for lounges and said "absolutely no problem".

We hit Cathay Pacific, chilled and took a shower. Walked to Qantas, drank an espresso, walked to centurion and ate lunch. Took the connection bus back to t5a where I am sitting in galleries south waiting for a gate to be assigned to our Frankfurt flight.

All in all it too roughly 3 hours for all the movement and to return to t5a.