What is the correct way to attribute FreeForm submissions to users? I'm using FreeForm and need to create a relationship between form submissions and the user that submitted them.  

To accomplish this I created a hidden variable on my form called userId.  I use overridesValues to set the userId to the current user before I render the form.  This "feels" wrong to me .. is there a better way to do this?   Is this userId already stored in the freemform data model (making what I'm doing uncessesary)?

{% requireLogin %} {#check user is logged in #}
{{ craft.freeform.form("employeeForm", {
  overrideValues: {
    userId: currentUser.id,
  }
}).render() }}
Actually saw that earlier in the documents: https://docs.solspace.com/craft/freeform/v3/overview/relations.html#overview