Wouldn’t it be slightly easier to just roll back to 8.0.10 and keep the CMC’s? 
I’m actually having a somewhat similar issue. May be entirely unrelated but I’m having the 8.0.10 session that I’m currently working on drop the audio output after it’s been open a while (maybe 10-20 mins). Seems to be related to plugins on the Stereo Out. When I remove the plugins, the sound returns. Do you have any plugins on the Stereo Out and if so, have you tried removing them?