Anyone here have success using Files Connect to attach files from Google Drive when in "reference" sharing setting?

We currently use the reference sharing setting to link "live" Drive files such as docs and sheets to records in Salesforce. However, with this setting enabled Drive files do not work as email attachments—even thought you can select the file and get a warning about sharing that file externally. If I update the sharing setting from "reference" to "copy", SF will copy the Drive file and create a duplicate File (which will be successfully attached to emails), but I can no longer reference a live Drive file if I want to store it on a record.

The interesting thing to note is that Drive files that were linked as a reference (rather than a copy) before I changed the sharing setting from reference to copy appear to still be listed as a reference file, although all newly created/importing Files from Drive are copies.

So back to my question: is it possible to use "reference" setting when linking Google Drive files to Salesforce records, but also get them to work as email attachments (presumably by copying the Drive file into Salesforce when it's sent, as happens when the "copy" setting is selected)?

Failing that, is there any way to remove Drive as an option when selecting a File to attach to an email when in reference mode? I'd prefer not to allow users the option of attaching a file when I know for certain that it won't be sent.

edit: @Neil Hayek