I think this OLD Article shows that Credo works as a Complement to existing Active Copper Cables rather than as a standalone solution.
The article talks about Credo in COMBINATION with Foxconn's latest Active Copper Cables. It also mentions Centec. Spectra7 is not specifically mentioned, but we know that Foxconn's Active Copper Cablles use Spectra7:
‘’The continuous demand to lower cost while increasing bandwidth in data centers requires on-going innovation of serial link technology,” said Jeff Twombly, vice president of business at Credo.
“The combination of FIT’s latest QSFP28 ACC and Credo’s low power, low latency 100G retimer devices provides a low cost alternative to conventional active optical cables (AOCs) for intra and inter-rack connections.”
https://www.credosemi.com/releases/2017/5/22/credo-and-fit-deliver-robust-10m-100g-active-copper-cable-solutions