I have never had an issue about whether powder is dropping, just whether the amount of the drop is correct.
The design and function of how the Star powder drop works, practically eliminates that concern, as long as you maintain powder in the tube.
When I first start, I cycle and weigh at least 5 drops, then check 5th and 10th charge for accuracy and consistency. After that every 50.
In my opinion, I have sufficient ambient light from overhead, and feel I do not require a dedicated press light.
I do however, verify powder is present in my Dillon 550.
Hope this helps.