Last night I flew QF400 from YMML-YSSY and found that ATC were consistently slow to assign further climb and descent clearances. I ended up levelling out 3 times in the climb and twice in the descent, whereas normally I'd get clearance in advance of reaching the assigned altitude.Is this a feature that is deliberately coded into RC4 to add a degree of real-world 'imperfection' or was it something else? My rates of climb and descent were within normal parameters for the 763.

surrounding traffic can cause delays for climb/descent clearancesjd

That would be it, plenty of QANTAS iron around me for the whole flight, thanks!