What do you do if your child's ultimate goal in life is sameness? What does THAT mean? He may only like a set number of foods, has few preferred activities and no interest in others. New is almost always viewed as non-preferred. Sound familiar?
How do you handle this? You could allow him to just avoid change. That doesn't seem very reasonable but the conflict it causes is so difficult. Am I speaking your language? Change and new things cause anxiety and the way a child with social difficulties functions is to put his heels in the ground. Why? He tries to avoid this very confusing world that seems constantly changing. This is why your child loves technology; it is programmed to work a certain way and it does. It is predictable. The social world has constant changes and new things are very difficult for this child to predict.
The best way to help your child is to gently "push" him to do things outside of his comfort zone. This may be sitting at a new chair at dinner. He may need a visual support, social story or verbal preparation for a few meals before you ask him to actually sit somewhere different. He may balk at it when asked. Why? The anxiety of the situation causes him to revert back to his digging his heels in. The visual will help as will verbal prompting of the steps he already has practiced. Take this slow. Only tackle a few things at a time.
Using a first ....then strategy may be helpful. He must try the "new thing" before he can have or do a ultra-preferred thing or activity. It will take a lot of patience but it will open up an opportunity to expand your child's world. It is a step to helping him live and adapt to people who look at things much different than he does. Good Luck . Let me know how it goes.