Not sure why you want to hardpan, ie which dry/wet signal you are referring to. The cue out will send any track you send to cue to your interface “as is”, ie the way it is being processed in your OT on the track. If you want to decide between the volumes of the “uncued” track (as comes out of your OT pre CUE) and the “cued” track (ie track affected by your iPad FX) you can use the OT’s studio mode for cue. In studio mode, you can control the track volume and cue send independently, so it works like a “Send to Aux” on your mixer or in your DAW. If this is what you are after, switching to cue mode and ditching the hardpan thing will allow you to simplify your setup.
If I read your issue correctly, your line outs are working but you can’t identify which of the “Hardware Input” options in AUM correspond to your Babyface’s physical inputs, correct?
I’d suggest here that you simplify your setup until you’ve worked it out. Here’s my suggestion, two scenarios:
Scenario A: IF your OT is your main mixer and your speakers are connected to the Main Outs of the OT
Send Cue Out of OT to Line in 3+4 of your Babyface. Send your Babyface Main Outs to OT’s Line ins (1&2 or 3&4 up to you). In AUM start with a blank project, add an audio track, as input select “hardware input > usb?” (? = you’ll have to try out all options till yo get a signal). The route that track to your Babyface outputs (click on the “bottom circle” of the track, select “hardware output” and then select the appropriate USB out -in this scenario your main outs - which you seem to have identified already). On your OT, set direct monitoring for the “return” input you chose to 127 OR use one track to set up a THRU machine and set it up to source the line ins you’ve chosen. You need to take this step to hear your return signal.
Scenario B: If you have a mixer or another audio interface that your OT and Babyface go into
Send Cue out to Babyface ins. Send Babyface main outs into a stereo track of your mixer. Set AUM the same as described above. No need for direct monitoring or THRU machine in this setup, as your mixer/interface will rout the audio to your main speaker source.
Please note: your hardware INPUTS and hardware OUTPUTS will almost certainly be handled separately by your Babyface Pro. In other words your “USB1” on “Inputs” has got nothing to do with your USB1 on “Outputs” - they may be named the same but they are different physical ports.
In AUM you’ll find all hardware INPUTS in the upper circle of an AUDIO track by clicking the “+” and choosing “Hardware Input”. You’ll find all the OUTPUTS, by clicking on the bottom circle of the same track and selecting “Hardware Output”.
You should be able to just cycle through your inputs on an audio track until you have a signal. Best to just loop something on the OT, send it to Cue, then cycle through the inputs until your meters show there’s a signal coming through.