It is a lot of info and I just did a quick read, but if I understand correctly....once you unplug everything and only plug the tuner back in, you get rid of the DSP and you have a better signal to work with. At that point, you can use a hacked set of RCA's directly connected to the wires coming from the DSP amp, into a GLI and then to your aftermarket amp. It eliminates a lot of wiring, tuning, and extra pieces.
I wish I only had the time this weekend.