I just performed the ZS7 mod as recommended by
@Slater. You're not kidding that there's a cavern beneath the 2-pin connector. To prevent shorts, I taped up the wires soldered in series and tucked them under the crossover, nestled everything inside that cavity, and gently put the 2-pin connector on top. Cleaned up the wiring to make sure the DD had breathing room as well, but maybe not as pretty as Slater's work (meh, it's going to be underneath a casing anyway).
Retesting everything and the A/B difference is...interesting. Granted, this is a brand-new pair and my ears are still adapting to the signature, but I think that haphazardly-placed crossover was choking airspace behind the DD. Bass quantity has gone up and I feel like things are generally airier in comparison. Today's home commute should help me figure out if the mod affected isolation, but if you're comfortable with tiny wires and don't have jittery fingers, I don't see why you wouldn't give it a shot.
Thanks again, Slater. Good observation. Baffles me why they just wrapped up all the slack and shoved it underneath the crossover when there was so much room in the corner.