Could you try the spoon fed food in a more comforting way like sat on your knee? As soon aa he takes it, put him next to you, then back in the chair (iyswim) that way, he will see it is ok to eat off the spoon.
I do agree that they are manipulative and very clever, even at this age, but you need to find the happy medium here, yes he is the child and should do as he's told. But actually he is a little person, with thoughts and feelings and there us something making him not like the spoon, so that needs to be addressed.
Missing lunch is one thing (i hope he has a nice big snack to fill him later) but I also agree missing two meals isn't on, he needs his fuel.
I would start small. Offering him a couple of spoons of something on your lap, then into the chair for his "normal food", then over time move him away from you and into the chair... and building up the amount of spoons you give him, until... he's spoon fed the whole meal.
It may be an independence thing for him, for all of this time he has been feeding himself, then all of a sudden he is being fed, with a weird object. So give him a spoon too. He may not even attempt to use it straight away, but let him realise, he will soon be able to feed him self still, just with the spoon.