I remember this project of a open hardware ZIF SSD using a commercial SMI controller. I think it is using the vendor firmware customized for his build.
https://hackaday.com/2022/10/30/zif-hdds-dying-out-heres-an-open-source-1-8-ssd/
Hackaday
ZIF HDDs Dying Out? Here’s An Open-Source 1.8″ SSDA lot of old technology runs on parts no longer produced – HDDs happen to be one such part, with IDE drives specifically being long out of vogue, and going extinct to natural causes. There…