Multichannel differences between VST3 and AU on Mac with latest development branch

MacOSX and iOS
1

My convolver supports multichannel. I use APH to test from time to time. I typically set maxChannelsOfNamedLayout = 128 in juce_AudioChannelSet.h, recompile and test it out, mostly on Mac using the Audio Unit plugin.

This worked on Juce 7.0.5, but I noticed a number of fixes on develop, and brought those down, recompiled on a Mac M1, Xcode 14.2 and Ventura 13.4.

Now I see the VST3 plugin support up to 7th order Ambisonics (untested):

7th order VST3
7th order VST3862×976 255 KB

But the AU plugin only supports up to 3rd order Ambisonics:

3rd order Audio Unit
3rd order Audio Unit997×1013 165 KB

I need 32 channels from the AU. Any ideas? Thanks.