ADAU1467 AEC-NR function question

Hi Guys:

    I have some question about adau1467 AEC-NR Block algorithm.

    At the moment i using it to build a framework and then He did have some effect.but i only using one channel to build it .Because it has to do FFT and IFFT in block schematic.and then i will ask the following question.

    1、when I am using more than three NR modules, and there is a problem with the pointer. Is there any restriction on adding the module? Otherwise, there will be overflow of internal variable space.

    2、In the use of AEC module, we will find that it takes up a lot of DM1 resources. I cut dm1 into dm0 in block algorithm, but it is useless, so I think I can only do aec-nr function of one channel or microphone. If I'm an array microphone, can I mix and do this function later, but I think there may be some unpredictable problems.

   3、How can i get the AEC license. sending email to license Official email ?What does he need from me?

   4 、when i input two channel audio and then using RMS module, and then mix up this channel  audio . output this channel. and add a volumn module.I found that I can't adjust the volume. Just delete the RMS module. Is it because my RMS module is limited?