If I understand things correctly, this is Linux namespaces limitation, so tools like Docker or Podman will not be able to support such mapping without support f

If I understand things correctly, this is Linux namespaces limitation, so tools like Docker or Podman will not be able to support such mapping without support from Linux. But I'm afraid the requirement for UIDs to be mapped 1:1 is fundamental, otherwise, say two container users 1000 and 0 are mapped to the same host user 1000. Who then should be displayed in the container as the owner of a file that is owned by the user 1000 on a host?