I use the crunchydata postgres operator which generates a secret with the connection URI - is there any way to use secretKeyRef to specify database configurations for spicedb-operator?

Yes but it expects a specific format (

datastore_uri

key with the full connection string). Does that work for the pg operator? If not could you open an issue on the operator repo?

I have a question for the spicedb-operator - is this configuration pattern possible?

Using Secrets as environment variables

https://kubernetes.io/docs/concepts/configuration/secret/#using-secrets-as-environment-variables