As an important detail of that interface which was quickly mentioned by Jamie, that interface won’t be able to be manually connected. The problem here is that as it stands a user would have no ability to evaluate whether the data being offered to the snap is indeed supposed to be used by that snap. For example, the interface might be named “pictures” but the paths might be “~/.ssh” or “~/.gnupg”. So this would indeed be used only on exceptional cases, and would need to pass through review first.
In the future we can lift that restriction by making interfaces more interactive. We’d need to prompt the user to accept the fact that the specific requested paths are being granted to the application, at connection time.
@pjbroad The interface suggested would effectively give what you’re asking for. The detail is that it’d need to pass through review first, which shouldn’t be a problem for you I assume. The other detail is that by not using the usual snap conventions, your snap will probably misbehave on rollbacks when there are data format differences.