Any ETA on "secure sharing" features mentioned at Ignite?

StephenRice, it looks like the "block download" feature is appearing in our tenant now, but this can only be applied/selected when sharing with "Anyone"? We have a need for this function, but scoped to specified individuals. To give you some more context, here is a scenario.

We're a University and have a department responsible for handling allegations of misconduct by students. That department stores any evidence provided in SharePoint and is required (not sure if by University policy or some accrediting body) to allow students to view (and ONLY view) that evidence. They've tried this using "protected" PDFs in the past, but discovered that not all PDF readers respected the protection settings created by Adobe Acrobat. For their purposes, it would be ideal if they could share the files specifically with the student and make use of the "block download" function to prevent them from downloading, printing, copy/pasting, etc. I understand that they'd still be able to screenshot it or take a picture with their smartphone, but, let's be honest, there are things out of our control. 

Might there be another way to set that "block download" flag on a file that's shared with specific users rather than using the "Anyone" audience? I know that using an appropriately-configured and secured "Label" (via Security & Compliance) is the best way to do this, but I have no access to S&C and those that do are "working on it" (with no ETA in site). So, I'm stuck trying to provide this level of secure file access with out-of-the-box features in O365.

Thanks for any help or advice you could provide.