I also did something like this a few years ago (with Go templating instead of Jsonnet), but we recently replaced it with Kustomize (https://kustomize.io/ https:

I also did something like this a few years ago (with Go templating instead of Jsonnet), but we recently replaced it with Kustomize (https://kustomize.io/ https://kustomize.io/) as it worked quite well for the basic use case of getting shared Kubernetes configs to deploy code to different environments at different times.