I'm sure what you what to happen.

If you have a file that's a hard link, it would get fully copied to the remote.

Remotes have no concept of hard links so if you have:

/dira/file.txt
/dirb/file.txt

On the same physical volume and want to copy it to a cloud remote, you get two copies as the cloud remotes have no idea/concept of hard links as those are physical file constraints.

In the scenario above, what would you want to happen on the remote?

If you have a file that's a hard link, it would get fully copied to the remote.

Yes, understood. Wastefully as many times as there are hard links.

Remotes have no concept of hard links

Is that universally true? AFAICT, SFTP supports hard links.

so if you have:

/dira/file.txt /dirb/file.txt

On the same physical volume and want to copy it to a cloud remote, you get two copies as the cloud remotes have no idea/concept of hard links as those are physical file constraints.

Again, I believe SFTP understands hard links. So when a remote is an SFTP server on a POSIX filesystem, there is no reason to not support hard links.

In the scenario above, what would you want to happen on the remote?

I would want the remote, which is an SFTP remote, to create hard links on it's POSIX file system.

So while, yes, many "cloud" providers don't support hard links, it is not universally true of all rclone remote types and where they are supported by a remote, they should be used.

Is that universally true? AFAICT, SFTP supports hard links.

So let me be specific, generally rclone uses cloud based remotes and most/many do not support hard links. Are the exceptions? Sure. I was speaking generally so thanks for clarifying as I didn't say all but I do see it was implied.

I would want the remote, which is an SFTP remote, to create hard links on it's POSIX file system.

As above, there are so many SFTP servers out there as some support / some don't. It's very dependent on what the SFTP does as if it is supported or not.

It's a very narrow use case in terms of rclone so it can be logged as an enhancement, but realistically unless you plan to implement, it will most likely sit unless someone else picks it up, sponsor someone to make the change or it'll just collect dust.

For anyone else who comes across this looking for hard-link preservation (and indeed, all of the rest of the rsync goodness, I was able to get rsync working over CryFS to have an encrypted remote such as rclone can do.