The problem here is more fundamental.

Lennart refused to make all the /etc/fstab options available in regular mount units. And yes, there was an issue, no I'm too tired to look for it. The wording was pretty much: "Give up, and gtfo, this is not going to happen. Just because."

I'm convinced that systemd can't be fixed by its current team of maintainers. They are just... untidy.

I don't know about you, but if I end up writing low-level code that _needs_ to know whether the mounted file system is "remote", I won't do that by comparing against a hard-coded list of filesystems inside PID0. Or by using wild heuristics ("if it's on a block device, then it's local").

I would put these heuristics in a helper tool that populates the default values for mount units. Then allow users to override them as needed. With a separate inspector tool to flag possible loops.