From File::SharedNFSLock:

It's in production use at our site, but if it doesn't work for you, I'm not surprised! ... I use the fact that hard links are (err, appear to be) atomic ... Basic unit tests are in place for this module. However, it is not extensively tested (Patches welcome!). While the module is used on production systems here, do your own testing since it may contain hidden race conditions.

You should probably carry over these possibly quite serious caveats into your documentation.