when i did this years ago, i ran up against a problem with a guitar part and a keyboard part. they were occupying the same space in the spectrum. it would be most correct to say that they were melodically interweaving with each other, but they were both so heavily distorted that i essentially had to choose one or the other. otherwise, i'd just get a distorted mess.
at the time, i picked the synth part and every version since has had the synth part. but the guitar part is worth bringing back in.
so, i'm going to try and take the synth part up and down a few octaves. playing with it.
this is the last major thing i have to do with this. after that, i'm just setting levels for the last few parts.
i may also try and compress the distortion out of the synth part so i can get that interweaving effect. the problem is that they're both at disaster-zone levels of distortion. i play with harmonic overlays fairly regularly, but you simply can't do close harmonies through such a damaged sound spectrum....you get one or the other. must choose.