Setting a user quota in ZFS which does not count snapshots

I love ZFS on Linux (RedHat 7), and users love the recovery that snapshots provide. The one problem that I have is that users will completely fill up their user quota then delete files expecting to immediately use up the free space. This does not work when using userquota, as snapshots count in userquota. reference quota would seem to be the solution, but I cannot see how to set a reference quota for a single user. The only solution would seem to be setting each user up with their own volume, but with hundreds of users, that is not practical.. I've checked the man pages, and google, and cannot find an example of this. Is this possible? Can someone provide an example for a user in the home directory.