ah, the actual reason that I switched is that the activity['actor']['url'] from instagram seems to be their instagram url, not their domain url. I took a brief look at the a-u code and I think this is the fallback when a real url isn't found...

    "actor": {
        "username": "_kylewm", 
        "displayName": "Kyle Mahan", 
        "url": "http://instagram.com/_kylewm", 
        "image": {
          "url": "http://images.ak.instagram.com/profiles/profile_504077259_75sq_1388273406.jpg"
        }, 
 
as far as procesing for non-bridgyy users, will we ever be parsing replies to a post from someone who is not signed up for bridgy?