not yet. but I think it's not that hard to do.
let me see if I can hack something together

Thanks. If you give me some clues I might try to make the enhancement.

it would be useful if you could generate a minimal repro that uses a sample dll (doesn't need to compile - dll might be 0 bytes)

As a couple of tests or a folder with all required files (source file, solution file, project file)?

yes a folder with all required files would be nice. I would then put this into our integration test suite

Here you have. http path must be changed!.

i001341.zip

please test the 2.40.7 version.
I added your sample repo as integration test and implemented a fix. but Im not completely sure if it works. so please see it as an alpha version that needs further testing.

Starting with a greenfield folder, it succesfully creates a project reference to the dll. But there are some undesirable behaviors:

• It copies the dll to a new local folder below the project folder: paket-files/library.dll. This is not needed because the library is already downloaded below the paket-files directory. Only the project reference should be created.
• When the reference is deleted in paket.references, it succesfully deletes the reference, but the mentioned new local file paket-files/library.dll is not deleted.
• When paket-files/library.dll is found below the project directory, the installation fails. So forced updates of the library will fail.
• If we already had the library referenced as a link in a content item, this is not deleted when the new reference is added (minor issue to be documented).

just fixed this. paket-files/library.dll is no longer copied.
regarding docs - could you please take a look at https://github.com/fsprojects/Paket/blob/master/docs/content/http-dependencies.md and send a PR with some docs improvements that you find useful? would help a lot