  Superconducting arrays often require specialized, high-density cryogenic
cabling capable of transporting electrical signals across temperature stages
with minimal loss, crosstalk, and thermal conductivity. We report improvements
to the design and fabrication of previously published superconducting 53 wt%
Nb-47 wt% Ti (Nb47Ti) FLexible coAXial ribbon cables (FLAX). We used 3D
electromagnetic simulations to inform design changes to improve the
characteristic impedance of the cable and the connector transition. We
increased the center conductor diameter from 0.003 inches to 0.005 inches which
lowered the cable characteristic impedance from $\sim$60 $\Omega$ to $\sim$53
$\Omega$. This change had a negligible impact on the computed heat load which
we estimate to be 5 nW per trace from 1 K to 100 mK with a 1-ft cable. This is
approximately half the heat load calculated for the smallest commercially
available superconducting coax. We also modified the transition board to
include a capacitive coupling between the upper ground plane and signal traces
that mitigates the inductive transition. We tested these changes in a 5-trace,
1-ft long cable at 4 K and found the microwave transmission improved from 6 dB
to 1.5 dB of attenuation at 8 GHz. This loss is comparable to commercial
superconducting coax and 3$\times$ lower than commercial NbTi-on-polyimide flex
cables at 8 GHz. The nearest-neighbor forward crosstalk remained less than -40
dB at 8 GHz. We compare key performance metrics with commercially available
superconducting coax and NbTi-on-polyimide flex cables and we share initial
progress on commercialization of this technology by Maybell Quantum Industries.
