After trying the above powder combo's a year or so back, I settled on the WW296 at slightly more that the above listed max with that slug.
That was the best combo both speed and accuracy in All of my 357's.
But depending on your launch platform you may want to stay right around the 15.0 grain level, if in a weaker, smaller gun.
ABSOLUTE BEST accuracy was obtained at 14.8grains for me, but with the very slight accuracy loss vs. a hefty velocity jump at the top end of the charts, I settled on a heavy charge.
I just have not had good results with AA9 in 357.
Hope that gives you some useful tidbits.