Thank you for clarifying! From zfs-allow.8 docs Example 2 [1] it looks like it should be possible, but I guess there are important details omitted from that document that make such a design nonviable in your case. I'm glad to hear that you are using system designs vetted by zfs experts.

[1]: https://openzfs.github.io/openzfs-docs/man/8/zfs-allow.8.htm...