What is your definition of "regular setup stuff". When you boot the new machine, it will ask you basic stuff like language, and to pair the remote, and I believe to connect to network. You can do all these, and the box will then be able to take any updates (firmware and/or software).
Then when you give it to your son, he only needs to connect to his wifi (easy enough), and add his IPTV provider credentials.
If you want to test it, you can possibly even use your IPTV server credentials to test the box, and then when you are done, you can easily delete the server entry, leaving it blank for your son to be able to enter a new server.
I do this all the time for friends and colleagues all the time. These boxes do NOT force you to sign into services like google play, etc...