Do home practice challenges actually help?

Optional and playful is the key. A five-minute challenge can be useful if the child can do it alone, adapt it to the space they have and there is no expectation to prove it happened. I would avoid leaderboards, video evidence or parents feeling they have failed if the week gets busy. You could frame it as “something to try if you fancy it” and occasionally ask players what they discovered. The challenge should support their relationship with the ball, not turn football into homework. Some children will do it every day, some once, some not at all. That is okay. Your main coaching responsibility is still the environment you provide when they are with you.