iPad Pro 11 type-c interface

My new iPad Pro 11 doesn't work with my audio equipment, because it no longer has the 3.5mm audio jack.  With the Pro 10.5 and Air 2, I use the lightning port to operate equipment and receive the audio input at the same time; and the 3.5 audio jack for audio out

I have tried many different type-c wires.  Some did not work (most likely because of cheep design), surprisingly one cord I didn't expect to work was the type-c to type-b (looks like a small square on-top of a bigger square).  The iPad didn't fully identify the equipment, but the audio did work both in and out.  But in all cases when the cable worked for my amp, the iPad could not be made to send audio out to my PA system or receiver.

I can plug my amp into the type-c and apps can receive the amp, but this put all backing track audio from the iPad out to the amp and it sounded horrific.

I tried to send the audio out via Bluetooth 2 meters away, and it is delayed too much to work with the visual ques to play along with sheet music and other apps.  (All the companies I have contacted agree that Bluetooth will never work, but I had to try. It's so much faster now than it was 10 or 20 years ago. I thought this problem was fixed because, for the first time I don't have this problem with my Bluetooth headphones, watching video.  More testing will be required, for me to determine if this do to the receiving Bluetooth device or the iPad transmitting the signal or both.)

I tried a few different type-c to type-c and 3.5mm audio adapters and the type-c port would only work for charging. 

I also tried a type-c hub, with one type-c going to the amp and one type-c to 3.5mm audio.  This makes it a software issue, as the iPad sent music out to the 3.5mm for 2-3 second and then the amp for about 1 second. 

I have also tried a few other audio interfaces (adapters made just for the iPad) and every time the audio worked, it sent all audio in and out to the same device.  Therefore, without the 3.5mm all of my equipment that I use with my iPad in the past is now defunct and there are no new equipment on the market yet to address this address this problem and/or replace my old equipment with (some of it I purchased just last year). 

I have contacted three of the companies that make apps that I use and two hardware companies that make the equipment I use.  No solution yet.

In my next experiment, I am planning to hack the usb port on one of my amps to see if I can isolate the audio in from the iPad and install a 3.5mm audio jack at that point.

Can Apple fix this by building in a control for users, or an app to run in the background, or help app builders understand how they can fix this?  I know it can be done because one (only one) of the apps that I use lets me choose which mic I want as an input, even when I tried the hub.  None of the apps I use let me choose the output.

It's no wonder why I'm still using my Air 2.  As my eyesight is getting worse and I would love to replace mine with the big iPad Pro, but this problem is going to have to be fixed first.  It takes up to much desk space, I'm not lugging that big thing around with me everywhere I go all day, but it would be awesome for the music class room and the house.