Ok, I think I've answered my own question regarding how to record backing tracks along with your own instrument.

I'm using a free audio driver called SoundFlower (ver 2.0 beta2).

https://github.com/mattingalls/Soundflower/releases/download/2.0b2/Soundflower-2.0b2.dmg

To Capture audio open Preferences / Sound and set "Output" to "SoundFlower 2ch" instead of System Audio. You won't hear your audio until you set it back to Headphones, your Guitar Interface, or external DAC.

In Logic Pro, GarageBand, ProTools, Cubase or your DAW of choice, open Preferences and set "Input" to SoundFlower 2ch.

ARM your track, hit Record and then tab over to your browser, YouTube or wherever you want to capture audio from and hit Play.

It's not economical nor efficient, but it gets the job done. I'm still looking for a way to do the same thing using iPad guitar processing apps BiasFX and ToneStack namely.

Here are the first couple I put together. The Tesla track is backed by the whole band, I need to learn and record the leads which isn't easy.

https://soundcloud.com/private-profile-441207792/judas-priest-heading-out-to

https://soundcloud.com/private-profile-441207792/tesla-modern-day-cowboy-with

If anyone knows a more efficient way of recording with backing tracks please share.

Thanks!!