right, it's really impossible for Audyssey to apply separate correction to A and B because they are a split signal -- both "A" and "B" speakers are sent the exact same thing. It doesn't really make any sense to use the correction filters for your "A" speakers on your second set of "B" speakers, since they will be different speakers, in a different position, and thus require different correction!
Basically, if you want to have a secondary pair of "dedicated two channel" speakers, you will probably need to diddle with the Manual EQ.
I thought this was the whole point of B posts, so I'm surprised it's not supported by Audyssey.
Audyssey doesn't make these decisions, Denon does -- as with anything, it's a question of cost and limited resources, in this case the DSP and memory available. No consumer AVR unit can store more than one Audyssey calibration at a time.... and honestly can you blame Denon for not spending the money to allow this happen? How many people use the "B" speakers and demand a second Audyssey correction for them? It seems clear that the audience isn't there for Denon to spend the money upgrading the available memory and DSP resources to enable this functionality....