Yes, I would remove them all. He will be angry but he will soon get over it. As long as he has the stashes he will try to defend them. He will take that aggression out on you. We have seen pics of literal blood baths from aggressive squirrels. These precious, cute little babies can become nasty little badgers. You’ve heard the saying, “don’t bite the hand that feeds you”…. well, they certainly will. Without hesitation. They will sink those incisors to the gum level into your finger or wherever.
If he has some in-shell nuts, you might let him keep ONE. Chip is a red squirrel, right? He is as cute as a button.
I read right over the part where he was bred in captivity. I just assumed you were in the US when I posted the Henry’s link. Your willingness to purchase the blocks makes that more likely. We don’t see captive bred often in the US but we do see captive bred squirrels in Asia. Those are very tough because they have almost no resources to keep them alive.
Yes, you have some work to do. It’s called tough love. You’re going to have to break Chip’s nut addiction.
The Henry’s blocks have a pecan base so he will probably like them. They are a supplement block and are packed with vitamins and minerals.