Mutt, I think that we may have had a minor discussion upon the weight impact of a nominally increased acceleration height Vs MAA a few thousand posts ago.
We use a minimum acceleration height of 1000 feet, irrespective of a lower MAA. There's no weight penalty as the calculation is based upon the required 1st/2nd obstacle clearance to the "real" MAA (e.g. 500 feet), and NOT upon the performance degradation suffered by using an increased acceleration altitude. If, for example, MAA was 500 feet with a 2nd segment gradient of 2.0% required to MAA, the degradation between 500 and 1000 feet is minor, usually of the order of -0.1% or so, but of no consequence in this phase as the obstacle has already been cleared.
In earlier times the philosophy DID consider the increased Pressure Height to the artificially increased MAA, but on 95% of occasions no weight penalty resulted as it usually meant using a slightly lower Assumed/Flex temperature. On the other 5% of occasions, weight did suffer. That particular philosophy is no longer used.
Regards,
Old Smokey