The Docker client (cli) is easy to port - it's mostly just an elaborate frontend to the socket/API. Every other OS just runs Linux in a VM. Focusing on integrating the VM with the usual development workflow is the lowest hanging fruit, provides the best ROI, and is relatively future-proof.
Unless you mean running containers in production - I think OCI is a much better target in that case.
I have been using it for more than a year now in both production and at home. So far so good. Even GPU works out of the box in rootless mode without requiring any special privileges.
edit: Redhat in production and Debian at home
honest question: is it any stable?
I ask because last time I read about podman on FreeBSD it was at like alpha/pre-beta stage of development.