220kts at porpa rover, just to clarify, if you hit porpa/rover at a speed greater than 220kts, you will exceed the splay that has been calculated for obstacle clearance based on that SID. However, if you are at a height greater than the obstacle clearance height for that point, then you are in no mans land, until you reach a specified obstacle clearance altitude, or established on a defined track, or above radar lsalt or MSA etc . Because there is no gradient specified, the 220 knots gauarantees you obstacle clearance at a gradient of 3.3% or less, and at an altitude of 120m (394')minimum. (Hence the 440/220kts in the MCDU).
Obviously a normal departure, with no performance degradation, you will exceed these figures, so once you have gauranteed obstacle clearance, either visually (Brave call in HKG), or once above Radar lsalt or sector MSA, do whatever speed you want. To remain "legal", maintain 220kts to MSA,or established on track after porpa/rover then accelerate.Obstacle clearance will be no longer and issue, and splays etc are no longer an issue. Clear as mud? See your jepps, ATC SIDs, turning departures.