I've got Sonobus and pt and Zoom all working together...
I created an aggregate device using the ZoomAudioDriver (in hindsight I could have used a multi output device or VB Cable (see later)) as its not listed in Zoom as a device.
After Ryans comment about sesionwire, I installed that and it gave me multiple virtual drivers (into / out of). I tried this but session link was a bit of a hassle to setup sessions and I'd already got the sonobus plugin and app connected.
I needed another virtual driver so I used a freeware one called VB audio cable. (
https://vb-audio.com/Cable/) I could have paid to have a multiple virtual drivers but I've got it working with the ZoomAudioDevice and VO audio cable driver. One for sending, one receiving.
I had problems before this just using the ZoomAudioDevice as Input and Output with feedback (duhhhh).
In pt IO, I setup two mono busses (To Zoom / From Zoom)
I put the sonobus plugin on a new mono aux, made the aux input the 'To Zoom' bus, gave it not output.
Made a new mono aux to receive Zoom, the input comes straight from the plugin. In the aux input dropdown choose plugin>SonoBus - Network audio...>Aux 1 Out.
Make a new private connection between the app and Sonobus plugin.
In the SonoBus app click the blue SonoBus graphic in the top left to set your IO settings. I used VB cable as input and ZoomAudioDriver as output.
In the SonoBus plugin, you need to route the audio back to pt. In the far right on the connection window is the monitor out box (just above the ping display). Choose Aux 1 Out.
I turned down the monitor sliders on both app and plugin as I thought that would help eliminate feedback. In the plugin settings (gear icon) you can set your send quality.
I tried to attach a picture of my pt routing but safari is blocking the upload popup.
Hopefully that everything, sorry for the rambling message.
Also if you want an auto talkback plugin check out Bob Perry ATC2, its just like SourceTalkback but its $15 not $125. Does exactly the same things. Mutes talkback when pt timeline is running, dims master output, can be triggered with midi. I used my phone to trigger the talkback with a free iOS app called midi box and connecting my phone to my Mac via a networked session in Audio Midi Setup.
https://www.bobperry-audio.com/shop/bob-perry-atc-2/