So, about the hard pauses, it goes back to when I used to play AVNs. There were a handful of scenes which didn't necessarily contain a lot of dialogue but they had some renders which I wanted to look at. The problem with ren'py is that if you don't add a hard pause and you let the scene progress automatically, when you rollback you will miss that scene which progressed automatically. College Kings for example had a couple of scenes like that where if they didn't contain dialogue, the renders would progress automatically and when I rolled back I couldn't look at that specific picture that I wanted to see. I don't know if you can understand my point but it's something that gives players more freedom to see everything. Also, there may be some scenes which aren't that interesting for the average person to look at, but a player like myself would appreciate that hard pause which would give me the time I need to process a picture if I want to.
Now, with that out of the way, if you're talking about a black screen which has a hard pause, that is not intended. With black screens I tend to make them progress automatically because there is no need for someone to look at a black screen. I can't remember if there were any cases like this but if there are I'm sorry and I will provide a fix for the next update.