Combination of Audio through USB OTG DAC, changing to BT 2-way Phone/Voice commands, and back to USB (Motorcycle setup)

This setup is complex, but really the killer audio setup for motorcycle riders. I now run Android 6+, but I don't have any indication that SA cares about that. I've read about co-pilot helping with some delayed notifications for some apps, so that's something I'd look into after I get this initial set running.

I couldn't get media to play through OTG until I found SA Pro (perhaps the most valuable app I have ever used) and can get USB OTG media output just fine on any version of Android (stock, AOSP, CM), but it's integrating concurrent BT phone that is the challenge.

Setup/Devices:
1. GoneMadMediaPlayer Pro
2. SoundAbout Pro
3. USB OTG - All my USB cables are OTG and my audio cables are 4 pole, however, the USB OTG output is to an external DAC (DragonFly 2) and that is only 1-way which gives much better sound, but make the setup complex because I have to run audio output through OTG/Audio cables and any return through BT. Of note, when I want a 2-way connection, I need the USB OTG connection to shut and go exclusively to BT (I'm just fine with that).
4. Sena 20S helmet communication system that has 2-way BT 4.1 A2DP, microphone for phone and voice commands, and 4 pole AUX media input and headphone output (limited by the one-way DAC to the 4 pole lines are basically moot) to let the USB audio run right through it. It's the 'mac daddy' motorcycle helmet device that supports nearly every kind of connection under the sun. It establishes a BT connection on boot to Android and like a BT headset, doesn't open it until asked to, letting the USB OTG Aux audio passes through just fine.
5. Android device(s) are both rooted. LG G3 and Nexus 7 2013 running MM 6.01. The G3 is using a CM-based ROM (Bliss) and the N7 is using an AOSP-based ROM (Oct-OS), but SA seems to neutralize any OS differences (why SA is so awesome)

Primary Setup Help:
Android senses audio output through USB, BT, or the standard audio/headphone jack. No surprise, it passes any audio output to the USB OTG (notifications and phone output), but doesn't recognize USB OTG as a headphone device. With each device along the way having options to try to 'help' with sensing changes in signal type (USB, Aux/Headphone, BT), it complicates things and I'm pretty sure SA can manage it.

Setup I want to work:
What works (pure audio): Android USB OTG output->DAC->audio line from DAC into AUX input of Sena device, headphone output of Sena to my ears (absolute beauty). I've done this with no issues and it even picks up notifications and other audio prompts like the ring for incoming calls, notifications from Waze and other apps (as it should as there is an open audio connection through USB OTG). My Android is most often in my jacket, so I can't use my hands even if I wanted. I've set SA to use USB host and USB disable client and pretty much left all other settings alone. This gives me the best audio path possible, but it's only one way from phone->ears. Pretty good, but the Sena is now a paperweight.

What I need help with: Because the DAC blocks the return audio path that the 4 pole lines support, I need to use BT for phone. This is where the beauty of the Sena comes in because it has all the controls to sense the BT call, answer it and stay in BT until the call is over and switch back to the AUX audio line (the USB OTG, DAC...). In BT mode it is fully 2-way and can issue voice commands (SA listener or a variety of Tasker plugins) and return any audio response from Android.

NOTE: When I hear a notification or phone call over the USB/Audio connection, I press a button on the Sena (on my helmet) to activate the BT connection and enable the 2-way BT (just like any BT headset).. I do the same if I want to issue a voice command to Android. In both cases, I press a button on the Sena to tell the Sena to shut the USB/Aux input and open the BT connection. That's when I initiate a change - I'm not sure which device senses the end of a phone call. When someone hangs up, it must be Android. When I hang up, I press a button on the Sena to stop the BT connection. To initiate a voice command, I press a button on the Sena to open the BT connection and pause the Aux signal.

To wrap it up: How do I configure SA to route audio from my Android music player running over USB OTG, when phone calls come in and I press the button on the Sena to open the BT connection, shut the USB audio signal (I'd be ok with the music player pausing or not pausing), use the open, 2-way BT connection from Sena to Android, and when done, shut the BT connection and resume the USB audio signal.

I honestly think SA can handle it all, but I don't know how to configure it. HELP!

I'm a geek, so I understand how to use Tasker to watch for intents and other items in the catlog if that is what is needed.