Hmm, a convenient idea at first, but just like the Official Ubuntu or Debian images that serve as the base images for ROS, our ROS images similarly serve as a primary starting platform for many application, be it continuous integration or target deployment, etc. I would concur with @computermouth that including qemu into the official ROS images may be too much of a niche use case to justify the larger base image size that would require additional bandwidth when shipping and storage from resource constrained embedded targets. Additionally, the current multi-arch generator setup is such that the dockerfiles themselves are designed to be architecture agnostic, keeping it simple to add support for future platforms as they emerge. Necessitating platform specific alterations would complicate mainece a bit.
I didn’t yet reference this given some issues related to this capability on ubuntu and debian [1], and so instead opted for giving a legacy example of mounting the files I know works currently. However, I suspect once some additional issues [2,3] (thanks for starting those by the way, @computermouth) have been patched upstream, then mounting or baking qemu files inside the image should no longer be necessary. Testing with my latest apt sources still failes, but please report back @computermouth when those patches make into debian and ubuntu release.
[1] Qemu instruction translation for ARM · Issue #56 · docker/for-linux · GitHub
[2] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=868217
[3] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=868030