I'm assuming that you're querying the "level" acceleration bit?
As far as I'm aware there's no reason that you HAVE to perform a level acc. - all that the chart is signifying is that you may do so if you need/want to. As far as I know, the noise abatement procedures (both A and B) are actually designed for a level acceleration segment, basically to cover the engine-out case, but if all the donks are turning and burning there's no reason we can't do a climbing acceleration - it's entirely up to us. In the SID that you quote, the 4000' restriction is to keep you above the high ground in the vicinity - once you get to 4000' you will be able to accelerate in level flight and still miss the hills, even with an engine out. If they're all still in running order you are perfectly at liberty to continue the climb whilst cleaning up.
Hope I understood your question right (and that my gen. is correct
)