Melty puffs are not food, there are a baby version of Cheetos, an extruded snack made of corn flour and oil. Given the absence of salt, evaporated veggies powder are added to give saltiness from the minerals and putting a big picture of said vegetable on packet whereas actual content is a few%
Most industrial finger food labeled as "great for coordination" is pure junk which tastes like nothing in real life and is engineered to fit a baby's taste, so if your baby food are baby junk food such a puffs, baby crisps, baby rusk, baby rice cakes, ..... you are just putting your DS in the fast lane to develop a strong taste preference for ultra processed food.
Think of the food you want your son to grow up eating and focus on that. Finger food was invented for people standing up at parties and needing to be able to eat without cutlery, with one hand holding the plate, so most finger food have always been party food.
As a non-brit, I find this whole spoon vs finger very puzzling. Especially the (Marketing) claims that finger food are needed for development. French kids are not known to have particular development delays with hand coordination (I would also argue, the cursive we learn at school is ten fold harder than the one taught in UK schools). Paediatricians tell us to use spoons for food a spoon is used for (soups, mash, stew, soupy risottos) , a baby fork for a soft version of the food we use a fork for, and fingers, you get if, for food you eat with your fingers, such a blueberries, the hard end of a baguette, ... French kids are also known to eat whatever they are given and open to new foods.
Focus on the quality of the food, not the way it reaches the mouth . Understand how deglutition and salivation works to lubricate the food, think wider with more soups to which later you can add small bits, like baby pasta, or minuscule pieces of meat, make sure to include lentils and other pulses, dhals and the Italian minestrone which at first you blend in a very liquidy form, but then week after week, you introduce hall liquid half dense.
Don't overload the spoon until mastication is well mastered. Put just a tiny amount on it. Imagine if someone gave you a full spoon of mash which you have to swallow without chewing and releasing saliva. It would get stuck . A way to stimulate chewing is to put a very small amount on tongue. I really can't understand how such a crucial development phase is left unguided by the NHS, and mothers have to rely on social media or some trust (and when you see the food these suggest, no wonder, the amount of fussy kids UK has. Tasteless)
You have this amazing taste window opportunity in which kids are more prone to accept non sweet tasting food, embrace it. Roast a variety of vegetables in the oven, use garlic, onion, rosemary to flavour it. Then blend it or use the back of a fork to make it more or less mushy. Cook some rice, with a fistful of lentils in an homemade broth, and serve it with some liquid left, a small bit of butter or extravirgin olive oil. Bonus if you add some real Italian parmesan.
Don't waste this window on baby junk, he will get plenty of it in no time.