I thought that the most proper way to double track something was to actually record another take and try to reach that 99,9% as similar as the original one. That's what I've seen all music producers teach so far, instead of copying the take to another track into the DAW. I see that all the sound engineering you did over the tracks, I mean by using different amps for both, and some other tone modifications, helped on a good result by the end of the process. That would save guitarrists some time in studio sessions, but I wonder if it's worth it.
This Is not double tracking, i copied the track just to have It in 2 channels, i could have done a send from One Channel to the other but was simpler to understand like this
The difference here is that he's basically re-created John's actual chain (minus all the pedals etc.) which was essentially one guitar signal being split into two and each going into their own separate Marshall amps which gives a less mono and more interesting tone WITHOUT making it sound like two different guitars playing which is a different from double tracking where you WANT them to sound different so you get that super wide "doubled" effect. Both of these effects are different but equally as valid when producing so it just boils down to the sound you're trying to go for
