Session, Meteor.user() unavailable when Safari is set to prevent cross site tracking

I have an app that by default runs within an iframe. The parent window is a different domain. The user logs in inside the iframe.

However with Safari set to prevent cross-site tracking… when an already logged in user visits the app URL outside of the iframe, none of his user info is carried over – he’s logged out, and Meteor.user() returns null. Session variables also don’t carry over.

Is there any way to bypass Safari’s preventing of cross site tracking?