Inter-app audio replacement?

I have one iOS app that is an iPad touchscreen virtual musical instrument. I have another app that is an audio visualizer (36-th octave spectrum analyzer). I used to use inter-app audio to pipe audio samples from the first app to either the second app, or to GarageBand for recording. But inter-app audio has been deprecated.

My question is what is Apple's suggested method (API's etc.) to get audio samples generated in one UI app to play and display in another UI app (say on an iPad, where both apps can be on the display) in performance-near-real-time without using inter-app audio?
I think you're supposed to use AUv3 audio units and instead let the UI be loaded into the AU hosting app.
Although you wrote my goto AUv3 sample code (auv3test5) so I guess there's some reason why AUv3 is not a solution to your problem.
Inter-app audio replacement?
 
 
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