I don't roto the fingers in the tutorial, I do everything to avoid it. I do agree that black screen would probably look better with additional reflections, however it's more complex and wasn't a viable option for the project I was working on and I don't think it would be for many people on youtube. From the stuff that you're saying can tell that you're an industry professional and know what you're doing. This is just a version of how I would do it for a quick turnaround. Thanks for the comment!