Yes, I have tried the chat and they simply said they can not activate if not purchased from Sprint or Google.
I don't think it would matter. But I know its nearly impossible to get a phone added to the system. What is sounds like is that Sprint has a internal database of "Sprint" phones. If it's not on the list, than its not allow.
I will keep my journey up to date on getting this activated. If I don't find a resolution, i'm just going to order one from Google Play and sell mine on CL.