Acoustic Zen, Analysis Plus are both UPOCC copper cables made by the same company, as are the Harmonic Tech cables I offer, and Wireworld, DH Labs, and many, many more... they are all variations on a the same theme and IMO it takes a lot to do better, and they may get to be too expensive vs the speakers. You may be best off just sticking with the AZ cables.
To make an improvement there are some copper cables that are better, most of them by "burning in" the cable with a Tesla coil. A24 and Jorma do this, and it results in better clarity and less warmth, but they charge a lot, these cables have massive markups. Kubala Sosna and Tara also make higher end copper cables that you might like better vs AZ.
UPOCC silver is better still, but too revealing for most and often this is "solved" by using heavy gauges which get very expensive. For example Wireworld and Siltech offer 17g IC cables, which is more like speaker cable gauges, and kind of ridiculous for the signal leg of an IC cable going into high impedance termination. In any case UPOCC silver is excellent but too "thin" for many, and good implementations tend to be very expensive.
I use a UPOCC silver/gold alloy, the gold adds some warmth without reducing resolution as much as copper does, and I now offer 2 levels, one which I feel is most accurate (D4 and the new S4 SC) and one that is adding some additional warmth (D5 and the new S5 SC, which is also my current SMSG). I'd be happy to let you demo my OCC silver/gold alloy speaker cables, just shoot me a PM. They are still very expensive but I don't need to use excessive gauge to get the tone right, so not as expensive as most UPOCC silver options, and better tone.