I do it mostly at the beginning before uploading to see, if it fits my quality standard I set for my channel.
Like this one video took 3-4 days to make, since I worked hard to make my commentary decent or good.
Now it took quite a while and thank God the subscribers are patient which I thank them for allowing me some time.
I did that, because I'm great at technical side since I have Adobe packet, but I want it good on every aspect of the video like editing, commentary, quality, length etc
Also since subscribers will hear my commentary style and voice for the first time, so i wanted to make it worth to watch.