No. If the candidate spends four hours on a take-home it is basically a moral obligation that you give feedback. The exchange is literally unbalanced here. You

No. If the candidate spends four hours on a take-home it is basically a moral obligation that you give feedback. The exchange is literally unbalanced here. You ask for four hours from the candidate. The candidate asks for 1 hour from you for feedback. The candidate is also doing things on top of existing work to spend time and energy on a take-home. There's no two ways about it. Morally it's the wrong thing to do.