You're losing me because I'm not sure quite what you're trying to do. You're recording two separate signals - one DI and one miked from the amp. Check. But then you mention using the channel fader to control output of the recorded track while listening to the miked amp. By the "recorded" track, do you mean the dry track? And by listening to the miked amp, do you mean while you/re playing, listening to the recorded track of the miked amp, or listening to the dry track feeding the miked amp, which you are then going to re-record?
When you say you want the same flexibility with amps that you get with VSTs, a VST is
always re-amping because it's always processing a dry signal. So, maybe all you really need to do is clone the track with the dry guitar part, and insert the external insert in the clone so you can do your thing with the amp. Meanwhile, you can put a VST on the original dry track. As there will likely be different amounts of delay, you can insert a channel tools in the earlier track to dial in a matching amount of delay.
Then you can listen to both tracks simultaneously, do an opposite mute group so you can A/B the two, bypass the VST, etc. You would also have independent control over the volume for each track.
You could also just split the guitar so it only gets recorded dry, while the other split goes to the amp which you can set up for the right feel for your playing. After recording your part, clone the dry track and start playing around with the amp sound.
Maybe I'm not understanding exactly what it is you want to do...if you could explain the goal rather than the process you're trying to use to implement the goal, I might be able to provide a better solution. But it seems to me that cloning the dry track might be ideal.