Specifying architecture for for containerized workflow

I’d like to be able to choose container architecture (for architectures compatible with the runner’s architeture). For some images, this works because they have architecture-specific URLS:

jobs:
  hello:
    runs-on: ubuntu-20.04
    container: i386/debian:buster
...

Some images also have arch-specific tags, such as multiarch/qemu-user-static:i386 (bad example, but you get the idea).

But how would I do this for images that use multi-arch manifests? I can fetch these locally with podman pull --override-arch=i386, but docker pull doesn’t support that, and I haven’t found any hints how to do it in a github workflow.