Record from iOS Send/Return

I hooked up my my iPhone to the Send/Return usb and realized I can record digital audio directly from that.  I've found the iOS app Multitrack Daw works best.

The problem is getting all the mixer channels to play through the send.

If I set all the mixer channels to Crossfader A, move the crossfader to the left, and set the FX selector to Crossfader A, I can capture all the audio.  The problem is that I lose the ability to use the FX on a single channel, and I have to be careful not to bump the crossfader.

Feature request:  It would be great if I could send all the audio through the Send/Return independent of the FX selector. Maybe a setting change I could make.

Even better, I would love to record each track independently for easy editing later. If it could output all 4 channels separately, that would be perfect.  I tried connecting my iphone to the USB A/B outputs, but the iPhone won't recognize that as an input.  

I've seen a lot of disappointed posts that the DJMnxs2 didn't include the ability to record a set.  It seems like we're almost there with the iOS send/return with just a few tweaks.  Thanks.