Marfeel can reconcile logged-in users using different devices. If you want a user to be reconciled across all their used devices send its user ID:
window.marfeel.cmd.push(['compass', function(compass) {
compass.setSiteUserId(1);
}]);
Replace 1 with the specific user ID you use in the format of your choice.
The provided UserId will be the one used internally on the Single Customer View