Buyers have 10 days to leave a review=feedback for the seller, personally, I think 10 days are more than enough.
Could it be that you are referring to the 3 days time before auto-completion of the order?
That’s just the time you have until you need to either accept the delivery or ask for a modification/revision or the order gets auto-completed (auto-completion is necessary because some buyers simply order something and never show up again, and then the sellers would never get the money for the work they did).
So, even if you miss those 3 days in which you can ask for modification/revision and the order gets auto-completed, you still have 10 days to leave your public (and private) feedback.
You don’t need to do the accepting/completing and leaving feedback bit in one go. Most buyers do check and review right away but you don’t have to, you can accept a delivery, check it to your heart’s content and still post a review/feedback on that order for up to 10 days if you’re not sure it’s all good right after you receive and accept the delivery.