Audiobus: Use your music apps together.
What is Audiobus? — Audiobus is an award-winning music app for iPhone and iPad which lets you use your other music apps together. Chain effects on your favourite synth, run the output of apps or Audio Units into an app like GarageBand or Loopy, or select a different audio interface output for each app. Route MIDI between apps — drive a synth from a MIDI sequencer, or add an arpeggiator to your MIDI keyboard — or sync with your external MIDI gear. And control your entire setup from a MIDI controller.
Download on the App StoreAudiobus is the app that makes the rest of your setup better.
iOS 12.1.2 - Anyone download it? What did it break?
While Tim Cook is busy confusing his position as purveyor of planned obsolescence, with that of the center of the moral universe, his portable operating system still carries with it the stank of unreliability. As such I am hesitant to take the plunge, which is why I rely on all of you Guinea pigs. 
So if you've made it through the maze, please kindly share your experience with a reply. Your reward will be a small nugget of feel good, for knowing you contributed to the common benevolence.
Comments
I've only recently updated to 12.1.1.
I tend to update more frequently now, as I've joined the dots to my Air 2 screen rotation bug, and heat build-up, to when there's an update sitting waiting on it. Every time the update nag appears, my iPad starts playing up, so I just bite the bullet and do what I'm told.
How sad time we live, that this question is very valid, even worse that answer "nothing" would be very surprising ...
I need this core audio update badly. Model 15 Auv3 crackles all over the place in NS2 on my 3e gen ipad.
This!!! I need this so badly!
It’s been out over a month now and still not fixed. I am getting more and more pissed by this support and treating of customers.
I think 12.1.2 was just a phone update. iPad still shows 12.1.1 as most recent, and it has no problems with it. I don't understand the paranoia, especially for minor updates. I've been on iOS since 5 and the only time a major update screwed music stuff up was 8 or 9, I can't remember which.
It’s now 12.1.3 that will fix the core audio cpu problems with the 2018 pros. Very tempted to join the beta, I need to figure out if I need to return this new iPad or not within oh about 10 more days.