I haven't replied up to now as this is the one thing we don't have problems with. We have to do certain things in certain orders and some routines cannot be changed or else we would have not just a period of abbdabs but an entire day of them.
I'm hoping, like you, that it's a developmental stage to do with feeling in control. I know that my DD hates being little and hates other people treating her like a child/idiot, she also hates change and combined it all makes her feel out of control.
An example. She eats and drinks from normal cutlery and crockery but in the morning she still has milk in her anywayupcup. It's the first thing she asks for when she gets up, you have to put the cup on the tabe, she lies on the sofa in the same place with a cushion under her head, there cannot be anything else on the sofa. She drinks her milk in around 45 seconds then drops the cup on the floor. I can try to change this but she will cry and scream and cry and scream, be sick, cough, retch, lie on the floor and she won't forget it all day.
I know that I could spend a week weaning her off the behaviour but it's easier for me to go along with it, the whole thing takes three minutes from start to finish and it's over for the rest of the day. i'm sure she'll have grown out of it by the time she's ten, if she hasn't she can get her blimmin milk herself!!! The long and short of this behaviour is that I think "so what???", no child was scared for life for drinking milk out of an unsuitable receptacle..... although the 'playgroup mothers' would probably disagree
Now, I think the difference is that this foible is short and sweet, your DS's foible is going to affect your family at least three times a day, it will affect him at nursery, at friend's houses, at school..... and so I do feel that it's worth tackling rather than ignoring.
I would worry that it's a perpetuating thing where he just gets his plate layout right and looks for something else to focus on, his chair is right and so he looks at your chair... next week is it going to be the cutlery? He does sound so familiar to me in that he's willing to make a fight out of something for the sake of it and he's obviously treating this like a very serious hobby. If I knew the answer to your problem I'd be happier myself because we have the same thing going on here to a lesser degree. If I could understand my own DD2 I would be much more qualified to help you. There are just some children that aren't as straightforward as all the books or telly programmes would have you believe.
I'm hoping that with age will come more stable reasoning. I know that my own DD2 understands far too much of the wrong things and is too emotional to deal with a lot of things that life throws at her. She is incredibly sensitive to her own feelings and emotions and yet her emotional immaturity stops her from being able to control those feelings yet. Maybe I'm comparing him too closely to my own child but I get the feeling that there is a real similaity there.