[Buildah] Commit Multiarch images

I'm importing buildah into an application and I don't see a good way to commit multiarch images with github.com/containers/buildah/commit.go/Commit. I see that define.BuildOpts has a platform that is slice of structs that is used for building multi-arch images. The only architecture selection that i see for Commit, is a SystemContext.ArchitectureChoice, which is a single string. Do I have to use bud for multi-arch builds or is there a streamlined way to use Commit?